Browse Articles

COX-2 and Ki-67 in Breast Cancer: A New Perspective on Tumor Pathology and Progression

Background: Breast cancer is a formidable health issue, necessitating continuous research for improved prognostic and therapeutic strategies. Cycloxygenase-2 (COX-2) is linked to aggressive breast cancers, characterized by high-grade tumors, large size, lymph node involvement, HER-2 overexpression, and ERnegativity. Ki-67, which is used to measure cell growth, is predictive of chemotherapy response in ER and PR-negative breast cancers. High Ki-67 is associated with elevated recurrence rate and poorer prognosis. This study evaluated COX-2 andKi-67 expression in breast carcinoma and their correlation with clinicopathological features. Elevated Ki-67 is linked to higher recurrence and poorer prognosis. Methods: This retrospective cross-sectional study included 70 cases of invasive breast carcinoma diagnosed between August 2022 and July 2024. Immunohistochemistry was performed on formalin-𿿿xed, paraf𿿿n-embedded tissue sample for COX-2 andKi-67. COX-2 expression was scored based on quantity and intensity, while Ki-67was scored using St. Gallen Consensus thresholds. Associations were analyzedusing Pearson’s Chi-square or Fisher’s exact test, with p<0.05 consideredsigni𿿿cant. Results: The study revealed signi𿿿cant associations between high expressionlevels of COX-2, Ki-67 with aggressive tumor characteristics, including lrger tumor size, advanced stage, lymphovascular invasion (LVI), perinodal spread ad /PR negativity (P -<0.001). Though no signi𿿿cant association was found wth e, SBR(Scarff-Bloom-Richardson) grade, N stage, perineural invasion(PNI) and Her2 status. Conclusion: High COX-2 and Ki-67 expression correlate with aggressive breast cancer features, supporting their role as prognostic markers and potential therapeutic targets, particularly in hormone receptor-negative and triple-negative subtypes.

The Role of Transformative Research in Forensic Medicine: Advancing the Understanding of Cause, Manner, and Time Since Death

Forensic medicine plays a critical role in medico-legal investigations, particularly in determining the cause, manner, and time since death (TSD). In recent years, transformative research driven by interdisciplinary innovation and technological advancements has signi𿿿cantly enhanced forensic capabilities. Molecular autopsy, post-mortem imaging, and genomic pro𿿿ling are revolutionizingcause-of-death analysis, while digital forensics, injury biomechanics, and AI-based assessments are improving accuracy in identifying the manner of death. Meanwhile, emerging tools such as microbial forensics, RNA degradation studies, and then atomicrobiomics offer new potential for precise TSD estimation. Despite these advancements, implementation in India faces challenges due to infrastructural, educational, and policy constraints. This editorial emphasizes the need for ethical integration of transformative research into practice and urges investment in forensic research infrastructure and training to meet the evolving demands of justice delivery in India and beyond.

Study of Incidence and Severity of Coronary Artery Stenosis at Autopsy

Backgrounds: The occurrence of sudden cardiac death (SCD) has been continuously rising globally. Identi𿿿cation of modi𿿿able risk factors may help reduce theincidence of sudden cardiac death. Aims: This study aimed to evaluate the incidence, associated risk factors, myocardial ischemic changes, and the speci𿿿c arterial involvement in individuals who died due to a cardiac event. Material and method: The study was conducted at the Department of Forensic Medicine, Shri M. P. Shah Govt. Medical College, Jamnagar, from January 2023 to December 2023. A total of 110 cases of sudden death were included in the study. The heart was examined in these cases for both gross and myocardial analysis. Results: Left anterior descending artery (27.27%) was the most commonsite of stenosis, followed by left main artery (13.63%). The main feature was softening (8.18%) of myocardium, followed by hyperemia (4.54%) and myocardial𿿿brosis (3.63%) in the cases showing gross changes of ischemia. Conclusion: Sudden death caused by acute myocardial infarction mainly affects middle-aged individuals, with an increasing trend in younger people. The most common artery affected by stenosis was the left anterior descending artery, with most cases showing grade-3 or grade-4 stenosis. The left lateral wall is the most common site of infarction. Hypertension, Diabetes, nicotine consumption and drinking habits are the major risk factors. Nicotine and drinking habits can accelerate the development of coronary artery stenosis.

Design of resonant cavity for linear cavity single frequency fiber laser based on temperature controlled Fiber Bragg grating

In response to the limited tuning ability of traditional linear cavity single frequency fiber lasers caused by fixed cavity length and static feedback mechanism, a resonant cavity design for linear cavity single frequency fiber lasers based on temperature controlled fiber gratings is proposed. It achieves synergistic improvement in linewidth compression, power stability, and tuning range through thermal optical coupling modeling and intelligent algorithm collaborative search. The experimental results show that the average line width of the proposed scheme is 0.86 Hz (compared to 1.97 Hz and 1.59 Hz in the comparative scheme), the average tuning range is 38.0 nm (compared to 22.3 nm and 12.5 nm in the comparative scheme), and the average steady-state temperature control error is 0.81 °C (compared to 2.08 °C and 1.74 °C in the comparative scheme). Its average anti vibration offset is 0.75 kHz/g (compared to 2.67 kHz/g and 1.86 kHz/g in the comparative scheme), and its average photoelectric conversion efficiency is 57.60% (compared to 48.85% and 52.24% in the comparative scheme). In addition, the average floating-point computational cost of this scheme is 30.9 G (compared to 65.4 G and 40.7 G in the comparison scheme), the average running energy consumption is 13.1 W•h (compared to 66.9 W•h and 34.7 W•h in the comparison scheme), and the average memory usage is 24.92% (compared to 44.3% and 39.62% in the comparison scheme). It outperforms the comparative scheme in key indicators. The proposed dynamic tuning and multi-objective optimization platform can enhance the comprehensive performance boundary of lasers in complex environments, providing a highly stable light source design solution for precision spectral measurement, high-resolution sensing, and quantum communication fields.

Acute sprint performance responses to velocity-based versus traditional post activation performance enhancement interventions

The aim of this study was to compare the acute effects of velocity-based training (VBT), traditional strength training (TSG) and a non- strength control condition (CG) on sprint performance in trained individuals. In Session 1, anthropometric measurements of the participants were taken, and then 1 repetition maximum (1RM) squat values were determined after explanation, visual demonstration and familiarization of the sprint test and VBT method. In the second session, all participants performed a sprint test for the control condition. In the third session, participants completed the post activation performance enhancement (PAPE) protocol specific to their group after a standard warm-up and then performed sprint tests. In the 0–10 m distance, only the group × time interaction was significant (p = .014); a performance decrease (p = .016) was observed in the TSG group. In the 0–20 m sprint, time (p < .001), group (p = .043), and interaction (p = .003) effects were significant, and a significant performance increase was found in the VBT and TSG groups (p < .001). In the 0–30 m sprint, group (p = .015) and interaction (p < .001) effects were significant; an improvement was observed in the VBT group (p < .001) and a decrease in the TSG group (p = .039). In conclusion, this study demonstrated that the VBT protocol produced a more noticeable acute improvement in sprint performance compared to TSG, even when applied with the same load absolute.

Lightweight deep models based on domain adaptation and network pruning for breast cancer HER2 scoring: IHC vs. H&E histopathological images

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer is an aggressive cancer type that requires special diagnosis and treatment methods. Immunohistochemistry (IHC) staining effectively highlights relevant morphological structures within histopathological images yet can be expensive in terms of both labor and required laboratory equipment. Hematoxylin and eosin (H&E) images are more readily available and less expensive than IHC images as they are routinely performed for all patient samples. Lightweight models are well-suited for deployment on resource-constrained devices such as mobile phones and embedded systems, making them ideal for real-time diagnosis in rural regions and developing countries. In this study, IHC images are compared to H&E images for automatic HER2 scoring using lightweight deep models that incorporate several advanced techniques including network pruning, domain adaptation, and attention mechanisms. Two lightweight models are presented: PrunEff4 and ATHER2. PrunEff4 is a subset of EfficientNetV2B0 pruned to reduce the network parameters by ~80%. ATHER2 is a customized lightweight network that employs different sized convolutional filters along with a convolutional block attention module (CBAM). For PrunEff4 and ATHER2, transfer learning (pretraining on ImageNet) and domain-specific pretraining were employed, respectively. Different datasets were utilized in the development and final testing phases in order to effectively evaluate their generalization capability. In all experiments, both networks resulted in accuracies ranging from 97% to 100% for binary classifications and from 95.5% to 98.5% for multiclass classifications regardless of whether IHC or H&E images were utilized. Network pruning significantly reduced the network parameters whilst maintaining reliable performance. Domain-specific pretraining significantly enhanced performance, particularly in complex classification tasks such as HER2 scoring using H&E images and multiclass classifications. Both IHC and H&E stained images were suitable for deep learning-based HER2 scoring, given that the deep networks are efficiently trained for the specified task.

Correction: Frequent hemodialysis versus standard hemodialysis for people with kidney failure: Systematic review and meta-analysis of randomized controlled trials

Carpal tunnel syndrome and occupational co-exposure to biomechanical factors and neurotoxic chemicals using job-exposure matrices and self-reported exposure: Findings from the Constances cohort

Objective To study the association between occupational co-exposure to biomechanical risk factors, potentially neurotoxic chemicals and carpal tunnel syndrome (CTS) in a large cohort of French workers, using two methods to estimate chemical exposure: job-exposure matrices (JEM) and self-reported exposure. Methods A randomly selected sample of adults were included between 2012 and 2018 in the French cohort CONSTANCES. Self-reported CTS was assessed using the first self-administered follow-up questionnaire, sent out approximately one year after baseline. Occupational exposure to biomechanical risk factors was assessed using self-administered questionnaire completed at inclusion. Lifetime occupational exposure to chemicals was assessed using two different methods: with JEMs and with a self-administered questionnaire completed at inclusion. Multivariate logistic regression models were used to evaluate the association between co-exposure to biomechanical risk factors and chemicals and CTS, adjusted for personal and medical factors and stratified by gender. Results For the analysis using JEM assessment, 35,941 workers (16,920 men and 19,021 women) were included: 261 men (1.5%) and 469 women (2.5%) declared having CTS at follow-up. There was an association between CTS and the co-exposure group: OR=2.37 [1.60–3.44] in men and OR=2.09 [1.55–2.77] in women, compared to the non-exposed group. For the self-reported chemicals analysis, 42,168 workers (20,877 men and 21,291 women) were included: 338 men (1.6%) and 532 women (2.5%) declared having CTS at follow-up. There was an association between CTS and the co-exposure group: OR=3.07 [2.28–4.08] in men and OR=2.68 [1.91–3.66] in women, compared to the non-exposed group. Conclusions The study showed an association between self- reported CTS and co-exposure to biomechanical risk factors and chemicals. This finding should be confirmed using more objective case definition of CTS, e.g. carpal tunnel release surgery.

Risk prediction model for post-endoscopic retrograde cholangiopancreatography pancreatitis: A systematic review and meta-analysis

Background Post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) is the most common and clinically significant complication of ERCP, with an incidence of 3.5–9.7% in general populations and up to 14.7% in high-risk groups, leading to considerable morbidity, mortality, and healthcare costs. Although numerous multivariable prediction models have been developed, their predictor sets, methodological rigor, and clinical applicability remain highly variable. Method We conducted a PRISMA 2020–compliant systematic review and meta-analysis, prospectively registered in PROSPERO (CRD42024556967). Nine databases were searched to June 1, 2024, for studies developing or validating multivariable PEP risk prediction models. Data on study/model characteristics, predictors, and performance metrics were extracted. Risk of bias was assessed with PROBAST, and study quality with the Newcastle–Ottawa Scale. Random-effects meta-analyses pooled (i) PEP incidence, (ii) associations of individual predictors, and (iii) overall model performance. Results Twenty-four studies (26 models; n = 38,016) published from 2002–2024 were included, predominantly retrospective cohorts from East Asia (n = 16). The pooled PEP incidence was 8.48% (95% CI: 6.90–10.39%; I² = 96.4%), highest in East Asia and retrospective cohorts. Strongest predictors included pancreatic duct cannulation (OR=3.50), pancreatic injection (OR=3.50), previous pancreatitis (OR=3.32), and pancreatic guidewire use (OR=2.63); additional consistent factors were female sex, difficult cannulation, elevated bilirubin, low albumin, choledocholithiasis, and prolonged procedure time. The pooled odds ratio for model performance was 0.81 (95% CI: 0.78–0.84; I² = 83.5%), with AUCs ranging 0.560–0.915, though calibration was infrequently reported (38%) and external validation undertaken in only 46%. PROBAST indicated high overall risk of bias, chiefly in the analysis (92%) and participants (100%) domains. Conclusion Current PEP prediction models generally demonstrate moderate-to-high discrimination but are limited by suboptimal calibration, inadequate external validation, and methodological heterogeneity. Future research should adhere to TRIPOD guidelines, employ multicenter large-sample designs, retain continuous predictors, address missing data with robust imputation methods, and conduct comprehensive temporal, geographic, and domain-specific validation. Integration of artificial intelligence/machine learning with conventional modeling and embedding validated tools into clinical workflows may enhance predictive accuracy and real-world utility.

Gene profiles of peripheral white blood cells as potential predictors of pregnancy in embryo-recipient heifers

The bovine endometrium undergoes cellular, molecular, and functional changes to support embryo survival and development to term. These changes involve a finely coordinated series of events at both local and systemic levels. We postulated that circulating white blood cells (WBCs) could provide valuable biomarkers for predicting pregnancy success in heifers undergoing embryo transfer, when, sampled during both a preconception cycle and a conception cycle, before embryo transfer takes place. WBCs were isolated using PAXgene Blood RNA tubes collected from Holstein-Friesian heifers on Days 7 and 14 of a preconception estrous cycle (PCD7 and PCD14) and, after a rest cycle, on Day 7 of the subsequent estrous cycle (1ETD7) just before embryo transfer. Circulating progesterone and estrogens were assayed and pregnancy was confirmed by either uterine flushing and conceptus collection on Day 18 post-estrus, or the delivery of a healthy calf. Using a custom bovine gene expression microarray representing 19,479 unique transcript, comparison of transcriptomes between heifers classified as non-pregnant or pregnant revealed 1,240, 896 and 1,023 differentially expressed genes (DEGs) at PCD7, PCD14 and 1ETD7 respectively. Our bioinformatics analyses revealed that pregnancy failure after embryo transfer was associated with upstream regulators, biological functions, canonical pathways and gene networks related to inflammation, immunity, apoptosis and cell death regulation, cell proliferation, membrane compounds, lipid metabolism, oxygen transport and ions transport. The heifers classified as non-pregnant showed significant increased transcripts levels of PTGR1 at the three time points (PCD7, PCD14 and 1ETD7), AIF1 at PCD14, FNDC3B, IL15 and SERPINE1 at 1ETD7. Our findings highlight the potential of peripheral WBCs as a non-invasive source of biomarkers for predicting pregnancy outcomes, offering promising insights for improving pregnancy success when reproductive biotechnologies are used in mammalian females.

Heterogeneity among Venezuelan migrants in terms of coping in the context of the population exodus from Venezuela

This study concentrates on the unparalleled exodus of Venezuelans in recent years. By June 2024, the global population of Venezuelan migrants and refugees had reached 7.7 million, with 6.6 million settling in Latin America. This represents one of the most significant migration outflows of the 21st century, with estimated numbers exceeding those of emigration from Afghanistan, Ukraine and Syria. However, coping strategies and integration of Venezuelans in hosting countries is understudied phenomenon in comparison to other migration movements. The aim of this paper is to examine patterns of coping among Venezuelan migrants. By analyzing coping strategies, we aim to contribute to enhance understanding of the characteristics of Venezuelan migrants in the context of their adaptation in the host countries in Latin America. We conducted a survey among Venezuelan migrants in Peru in 2023. The study is based on the Lazarus and Folkman model of stress and coping. A Coping Strategy Inventory-SF instrument and a Latent Class Analysis method were employed to distinguish three homogeneous subgroups in terms of coping strategies. We found three such subgroups: problem engagers, hybrid engagers and mixed strategy users. These groups exhibit distinct characteristics with regards to age, sex, education and optimism. The article highlights the heterogeneity in the use of coping strategies among Venezuelan migrants. To the best of our knowledge, this study is the first one to apply Lazarus and Folkman’s model in conjunction with Latent Class Analysis in the field of migration studies. We strongly believe the proposed approach is useful in increasing our understanding about coping strategies and integration among migrant populations.

Genomic insights into Yanbian cattle: Breed-specific selective sweeps identified by whole-genome sequencing

The Chinese Yanbian Yellow cattle are an indigenous East Asian breed, closely related to the Korean Hanwoo cattle, and presumably share the same origin. However, unlike Hanwoo, which has undergone approximately 40 years of intensive artificial selection, Yanbian cattle have remained relatively unselected, preserving diverse genetic characteristics. In this study, we used whole-genome sequencing data from 45 individuals to investigate the unique traits in Yanbian cattle. To identify selective sweep regions and compare the results depending on different methods, we applied three approaches: cross-population extended haplotype homozygosity (XP-EHH), cross-population composite likelihood ratio (XP-CLR), and population branch statistics (PBS) based on the fixation index. Our results highlight the PEX14 gene and SIRT6 gene which play a role in cold adaptation, showing high XP-CLR value with clear evidence of fixation. Notably, the genomic region containing PEX14, which is involved in the browning of white adipose tissue in response to cold exposure, exhibited reduced nucleotide diversity and low Tajima’s D value in Yanbian cattle. This suggests that natural selection has acted on this gene to facilitate cold adaptation. Furthermore, genomic regions with early fixation events were primarily associated with environmental adaptation, whereas more recent fixation events were related to economically important traits. These findings enhance our understanding of the genomic characteristics of Yanbian cattle and support their potential for environmental adaptation, providing valuable insights for future improvement efforts.

Construction and validation of a prognostic model based on mitochondria-associated endoplasmic reticulum membranes gene signature in LUAD patients

Background Mitochondrial-associated endoplasmic reticulum membranes (MAM) are implicated in various malignancies, but their prognostic value in lung adenocarcinoma (LUAD) remains underexplored. Methods The Cancer Genome Atlas (TCGA) and GeneCards databases provided LUAD patient data and MAM-related genes. Differentially expressed genes (DEGs) were identified using the “Limma” package. Enrichment analyses included Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Set Variation Analysis (GSVA), and Gene Set Enrichment Analysis (GSEA). A prognostic risk model based on MAM genes was constructed using univariate, least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression analyses, validated by Receiver Operating Characteristic (ROC) curve analysis. PPI explored intergene relationships, while immune infiltration analysis investigated underlying mechanisms. The Human Protein Atlas (HPA) validated key gene protein expression, and drug sensitivity was analyzed using the Gene Set Cancer Analysis (GSCA) database. Finally, we also performed immunohistochemistry (IHC) staining in the tissue samples. Results A prognostic risk model with 3 MAM genes (ERO1A, SHC1, CCT6A) was established from 194 DEGs-MAM. Kaplan-Meier analysis showed significantly longer OS in the low-risk group. Enrichment analyses indicated MAM genes were primarily involved in immune-related pathways. TIMER analysis linked the 3 MAM genes with immune cell infiltration (CD8 + T cells, CD4 + T cells, B cells, macrophages). Expression and prognostic analyses revealed high expression of these mRNAs and proteins in LUAD tissues. Conclusions This study constructed a prognostic risk model for LUAD based on 3 MAM genes, revealing a potential link between MAM genes and LUAD, offering new insights into clinical treatment and prognosis.

Single-cell transcriptomic analysis reveals the association of Ccl6+Ccr2+Arg1+ macrophages with renal interstitial fibrosis in AKI

Background Acute kidney injury (AKI) is a major health burden with a high risk of progression to chronic kidney disease (CKD). Renal fibrosis is the ultimate outcome of CKD progression, with M2 macrophages playing a critical role by secreting pro-fibrotic factors. Chemokines can influence the progression of renal fibrosis by modulating macrophage polarization during the course of AKI. Methods An integrative analysis of single-cell transcriptomic data from kidneys of mice 7 days after AKI was performed to investigate ligand-receptor (LR) interactions between macrophages and to explore gene co-expression patterns during macrophage differentiation under AKI conditions. The AKI model was induced by unilateral ischemia-reperfusion injury (uIRI), and kidney samples were harvested at day 7. qPCR and WB were employed to measure the transcriptional levels of Ccl6, Ccr2, and M2 polarization markers in macrophages. Transwell assays were performed to evaluate the effect of Ccl6 on BMDMs migration. Cell proliferation was assessed using the Cell Counting Kit-8 (CCK-8) assay. Histological analysis was performed to assess the extent of kidney injury and fibrosis. Multiplex immunofluorescence analysis was conducted to assess the co-localization of Ccl6, Ccr2, and Arg1 expression. Results Through integrated analysis of multiple single-cell transcriptomic datasets from AKI, we identified strong interactions between Ccl6 and Ccr2 in renal macrophages at 7 days post-AKI. Additionally, co-expression of Ccl6, Ccr2, and Arg1 was observed in renal macrophages, and the abundance of Ccl6+Ccr2+Arg1+ cells was positively correlated with the severity of renal interstitial fibrosis. Ccl6 promoted the migration and M2 polarization of bone marrow-derived macrophages (BMDMs). Inhibition of Ccr2 in AKI mice reduced the infiltration of Arg1+ macrophages and attenuated the progression of renal fibrosis. Conclusion Targeting the Ccl6/Ccr2 axis may attenuate fibrotic progression and offers potential therapeutic insights for preventing the transition from AKI to CKD, a possibility that warrants further validation through future functional experiments.

Real-world trends in rheumatic disease rates among pregnancies in Ontario, Canada: A repeated cross-sectional study

Objective Despite increasing rheumatic disease prevalence among female individuals in Ontario, Canada, research is limited on whether this has translated to an increased proportion of pregnancies with rheumatic diseases. This study aimed to assess rheumatic disease rates among pregnant individuals in Ontario, Canada. Methods Using healthcare administrative claims databases from ICES, the proportion of pregnancies with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriatic arthritis (PsA), and ankylosing spondylitis (AS) from April 2011 to March 2021 were examined. The Mann-Kendall rank correlation test was used to test for trends in overall and individual rheumatic disease rates across the study period. Results In total, 1,408,100 pregnancies were recorded from fiscal years 2011–2020 in Ontario. Of these, 4,392 involved patients with rheumatic diseases. The overall rheumatic disease rate among pregnant individuals increased by 24% from 28.3 to 35.2 pregnancies per 10,000 over the study period (p = 0.0157). RA rates increased 22% from 11.1 to 13.5 per 10,000 (p = 0.0056), while PsA rates increased 111% from 0.9 to 1.9 per 10,000 (p = 0.0157). SLE, AS, and multiple rheumatic disease rates did not increase significantly. Conclusion The proportion of individuals with rheumatic diseases pursuing pregnancy in Ontario has increased, perhaps aided by advancements in disease diagnostics and treatment strategies. Further research is needed to link antirheumatic drug safety to pregnancy outcomes and explore other factors that may influence pregnancy rates among this patient population.

Substrate degradation and black soldier fly larvae bioconversion performance profile on co-digested oil palm biomass-based feedstock

Utilization of oil palm empty fruit bunches (OPEFB) is limited due to its low nutrient value but high lignocellulose content. Black soldier fly larvae (BSFL, Hermetia illucens L.) is capable of converting organic materials into high-value products. A co-digestion strategy combining low-nutrition OPEFB and other high-nutrient oil palm by-products, i.e., oil palm kernel meal (OPKM), is an approach to enhance the digestibility of oil palm biomass by BSFL. However, the information on the degradation of cellulose, hemicellulose, and lignin in OPKM, OPEFB, and their co-digested substrates after treatment with BSFL is scarce. Therefore, this experiment evaluated the growth and bioconversion potential of BSFL grown on OPKM, OPEFB, and their mixture. Three feed treatments of 100% OPEFB, 100% OPKM, and a mixture (50% OPEFB: 50% OPKM) were given to larvae to observe growth, bioconversion potential of BSFL, and substrate degradation. In addition, the changes of the substrates morphology were analyzed by scanning electron microscope (SEM). The results show that an increase of larval biomass weight by 634% was obtained in a substrates combination of OPEFB and OPKM, with a reduction in the feed conversion ratio to 84% in twenty-five days, as compared to a 100% OPEFB feed. SEM results indicate that the surface of OPKM and OPEFB altered significantly after being consumed by BSFL. Ultimately, the current findings confirmed the potential of BSFL as bioconversion agent in the utilization of low-nutrition organic materials with high lignocellulosic content, such as OPEFB by using co-digestion method. This finding is promising to be implemented for treatment and utilization of palm oil mills by-products.

NMR chemical shielding for solid-state systems using spin–orbit coupled ZORA GIPAW

We present an implementation of spin–orbit coupling (SOC) for the computation of nuclear magnetic resonance chemical shielding tensors within linear response theory. Our implementation in the Vienna Ab initio Simulation Package is tailored to solid-state systems by employing periodic boundary conditions and the gauge-including projector augmented waves approach. Relativistic effects are included on the level of the zeroth-order regular approximation (ZORA). We discuss the challenges posed by the PAW partial wave basis in describing SOC regarding chemical shielding tensors. Our method is in good agreement with existing local-basis ZORA implementations for a series of Sn, Hg, and Pb molecules and cluster approximations for crystalline systems.

Accordance of glass formation criteria: Entropic vs structural

Increasing evidences show the significance of low melting entropy in glass formation of substances. Our previous studies have uncovered the strong dependence between melting entropy in the eutectic mixtures and mixing enthalpy, which has been serving as an important reference for glass formation, showing that negative mixing enthalpy largely reduces the melting entropy. In this paper, we focused on the question as to how melting entropy is associated with another classical glass formation criterion of molecule/atom size difference of components. This question has been challenging since it is constantly entangled with the effect of mixing enthalpy and easily smeared. Here, four binary eutectics constituted by molecules with similar structural and chemical characteristics but quite different molecular size were elaborately selected. The extremely low mixing enthalpy measured in four eutectic systems using a C80 microcalorimeter guarantees the neglectable effect of the mixing enthalpy. The determination of melting entropies and the critical cooling rate for glass formation at the eutectic compositions for the four systems uncovers an evident relation between melting entropy and molecular size difference, confirming the compatibility of the two glass formation criteria for mixing systems.

The energy landscape of folding in <i>n</i>-C14H30 described by a machine-learned potential

Folding and unfolding in molecules as simple as short hydrocarbons and as complicated as large proteins continue to be an active research field. Here, we investigate folding in n-C14H30 using both density functional theory (DFT)/B3LYP calculations of 27 772 local minima and a kinetic transition network calculated for a previously reported potential energy surface (PES) obtained by fitting roughly 250 000 B3LYP energies. In addition to generating a database of minima and the transition states that connect them, these calculations and the PES based on them have been used to develop a simple and accurate model for the energy landscape. The model for the local minima is based on the number of gauche torsions as well as their interactions with neighbors and next-nearest neighbors, resulting in three parameters, which are fitted using the direct DFT results. The transition states are governed by 13 parameters based on differences between the two connected local minima. The model predicts that there are 44 530 local minima (not counting permutation-inversion isomers) connected by 525 028 transition states, including degenerate rearrangements. When compared to the actual stationary points, it achieves a minimum absolute energy error of 43 cm−1 for the local minima and 47 cm−1 for the transition state barriers connecting levels of different energy. The model also provides accurate predictions of the most kinetically relevant folding and unfolding pathways, for example, from very highly excited configurations to the global minimum. In addition, it facilitates the determination of a disconnectivity graph using the Cambridge Energy Landscapes programs.

Explicitly correlated geminal-based perturbation theory

An explicitly correlated extension of a pair-function based perturbation theory is presented. The reference is obtained as the antisymmetrized product of strongly orthogonal geminals, termed Strictly Localized Geminals (SLG), which can capture static correlation at mean-field cost. Geminals entering SLG are spin unrestricted, in general, and are expanded in the one-electron basis of the natural orbitals of the unrestricted Hartree–Fock wavefunction. Dynamic correlation is accounted for by perturbation theory (PT) at second order via a Dyall-like Hamiltonian acting as the zero-order operator [Földvári et al., J. Chem. Phys. 150, 034103 (2019)]. Here, an explicitly correlated (F12) correction is added to SLGPT2 to improve the description of dynamic correlation and enhance convergence with respect to the basis size. The resulting SLGPT2-F12 scheme inherits the fragmented structure of the SLGPT2 method, facilitating an efficient solution scheme. For numerical illustration, the SLGPT2-F12 approach is applied to small diradical systems, mainly focusing on singlet–triplet splittings.