Formation of Si nanopillars through partial sacrificing in super passivation reactive ion etching.

The vertical gate-all-around (VGAA) metal-oxide-semiconductor field-effect transistor (MOSFET) holds remarkable potential in the three-dimensional (3D) integrated circuits (ICs), primarily owing to its capacity for vertical integration. The Si nanopillar, a crucial channel in the VGAA MOSFET, is conventionally shaped via the reactive ion etching (RIE) system employing SF6/O2. Past studies have indicated that high O2gas conditions in RIE often result in Si grasses irregular nanostructures, such as nanospikes on the bottom surface, due to over-passivation. However, this study revealed that ultrahigh O2proportions (>70%), especially when combined with low chamber pressure, inhibit the development of Si grasses in the RIE system (termed as super passivation). Nevertheless, this scenario leads to the segmentation of the Si nanopillar. To address this issue, a proposed partial sacrificing method, achieved by sacrificing the upper segment of the nanopillar through prolonged processing time and reduced mask size, successfully yielded Si nanopillars without Si grasses. Furthermore, an empirical model was developed to elucidate how experimental parameters influence etching characteristics, encompassing etching rate and Si nanopillar shape, through a systematic examination of the RIE etching process. This research significantly contributes to the production of VGAA MOSFETs and 3D ICs.

Complete biodegradation of tetrabromobisphenol A through sequential anaerobic reductive dehalogenation and aerobic oxidation.

Tetrabromobisphenol A (TBBPA), a common brominated flame retardant and a notorious pollutant in anaerobic environments, resists aerobic degradation but can undergo reductive dehalogenation to produce bisphenol A (BPA), an endocrine disruptor. Conversely, BPA is resistant to anaerobic biodegradation but susceptible to aerobic degradation. Microbial degradation of TBBPA via anoxic/oxic processes is scarcely documented. We established an anaerobic microcosm for TBBPA dehalogenation to BPA facilitated by humin. Dehalobacter species increased with a growth yield of 1.5 × 108 cells per µmol Br- released, suggesting their role in TBBPA dehalogenation. We innovatively achieved complete and sustainable biodegradation of TBBPA in sand/soil columns columns, synergizing TBBPA reductive dehalogenation by anaerobic functional microbiota and BPA aerobic oxidation by Sphingomonas sp. strain TTNP3. Over 42 days, 95.11 % of the injected TBBPA in three batches was debrominated to BPA. Following injection of strain TTNP3 cells, 85.57 % of BPA was aerobically degraded. Aerobic BPA degradation column experiments also indicated that aeration and cell colonization significantly increased degradation rates. This treatment strategy provides valuable technical insights for complete TBBPA biodegradation and analogous contaminants.

Use of the Disposcope endoscope for awake orotracheal intubation in an elderly patient with a large vocal cord polyp -a case report.

BACKGROUND: Vocal cord polyps are commonly encountered in the otorhinolaryngology department. The risk of anesthesia is high in patients with large vocal cord polyps. Awake intubation with appropriate airway tools provides a favorable safety profile. CASE: We present the case of a 60-year-old male patient who had been suffering from a large vocal cord polyp for 16 years. Electronic laryngoscopy revealed that the vocal cord polyp was approximately 1.5 cm in diameter. The polyp had a pedicle and demonstrated synchronous motion with respiratory excursion. It covered almost the entire glottic area during inspiration and moved away from the glottis during expiration. A Disposcope endoscope was used for awake tracheal intubation, and the surgery was completed successfully. CONCLUSIONS: The Disposcope endoscope can be a useful option for awake orotracheal intubation in cases of anticipated difficult intubation and difficult facemask ventilation.

Strategies for Preventing Esophageal Stenosis After Endoscopic Submucosal Dissection and Progress in Stem Cell-Based Therapies.

Endoscopic submucosal dissection (ESD) has been widely used in the early neoplasia of the esophagus. However, postoperative esophageal stenosis is a big problem, particularly when a large circumferential proportion of esophageal mucosa is resected. Currently, there are several methods available to prevent esophageal stenosis after ESD, including steroid administration, esophageal stent implantation, and endoscopic balloon dilation (EBD). However, the therapeutic effects of these are not yet satisfactory. Stem cell-based therapies has shown promising potential in reconstructing tissue structure and restoring tissue function. In this study, we discussed the current strategies for preventing esophageal stenosis after ESD and perspectives of stem cell-based therapies for the prevention of esophageal stenosis.

Research on the Deformation Law of Foundation Excavation and Support Based on Fluid-Solid Coupling Theory.

To investigate the impact of underground water seepage and soil stress fields on the deformation of excavation and support structures, this study initially identified the key influencing factors on excavation deformation. Subsequently, through a finite element simulation analysis using Plaxis, this study explored the effects of critical factors, such as the excavation support form, groundwater lowering depth, permeability coefficient, excavation layer, and sequence on excavation deformation. Furthermore, a comprehensive consideration of various adverse factors was integrated to establish excavation support early warning thresholds, and optimal dewatering strategies. Finally, this study validated the simulation analysis through an on-site in situ testing with wireless sensors in the context of a physical construction site. The research results indicate that the internal support system within the excavation piles exhibited better stability compared to the external anchor support system, resulting in a 34.5% reduction in the overall deformation. Within the internal support system, the factors influencing the excavation deformation were ranked in the following order: water level (35.5%) > permeability coefficient (17.62%) > excavation layer (11.4%). High water levels, high permeability coefficients, and multi-layered soils were identified as the most unfavorable factors for excavation deformation. The maximum deformation under the coupled effect of these factors was established as the excavation support early warning threshold, and the optimal dewatering strategy involved lowering the water level at the excavation to 0.5 m below the excavation face. The on-site in situ monitoring data obtained through wireless sensors exhibited low discrepancies compared to the finite element simulation data, indicating the high precision of the finite element model for considering the fluid-structure interaction.

Deep skin diseases diagnostic system with Dual-channel Image and Extracted Text.

Background: Due to the lower reliability of laboratory tests, skin diseases are more suitable for diagnosis with AI models. There are limited AI dermatology diagnostic models combining images and text; few of these are for Asian populations, and few cover the most common types of diseases. Methods: Leveraging a dataset sourced from Asia comprising over 200,000 images and 220,000 medical records, we explored a deep learning-based system for Dual-channel images and extracted text for the diagnosis of skin diseases model DIET-AI to diagnose 31 skin diseases, which covers the majority of common skin diseases. From 1 September to 1 December 2021, we prospectively collected images from 6,043 cases and medical records from 15 hospitals in seven provinces in China. Then the performance of DIET-AI was compared with that of six doctors of different seniorities in the clinical dataset. Results: The average performance of DIET-AI in 31 diseases was not less than that of all the doctors of different seniorities. By comparing the area under the curve, sensitivity, and specificity, we demonstrate that the DIET-AI model is effective in clinical scenarios. In addition, medical records affect the performance of DIET-AI and physicians to varying degrees. Conclusion: This is the largest dermatological dataset for the Chinese demographic. For the first time, we built a Dual-channel image classification model on a non-cancer dermatitis dataset with both images and medical records and achieved comparable diagnostic performance to senior doctors about common skin diseases. It provides references for exploring the feasibility and performance evaluation of DIET-AI in clinical use afterward.

A new ferroptosis-related signature model including messenger RNAs and long non-coding RNAs predicts the prognosis of gastric cancer patients.

Background and Objectives: Gastric cancer (GC) is among the most malignant tumor types, which causes heavy healthy and economic burden to the people and societies all around the world. Establishment of an effective set of prognostic marker will benefit a lot to the treatment of GC patients clinically. Ferroptosis is a newly identified regulated cell death modality, with tight relevance with GC development. However, its application in the prognosis of GC has not been studied in detail. Deregulated messenger RNA (mRNA) and long non-coding RNA (lncRNA) expression profile in tumor can serve as novel prognostic marker for predicting the survival and cancer relapse in patients. Methods: We downloaded ferroptosis-related gene expression microarray data, clinicopathologic information and a list of 259 ferroptosis-related genes from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and Ferroptosis database, respectively. Then, correlation analysis, univariate and multivariate Cox regression analysis were used to construct a novel prognostic model for GC. Then, we validated the model in the GEO datasets. Finally, we evaluated the differences in immune microenvironment between high- and low-risk groups. Results: We utilized the ferroptosis-related mRNA and lncRNA profile to successfully construct a prognostic model (incorporating 2 mRNAs and 15 lncRNAs) in GC. Our model, integrating diverse clinical traits and critical factors of GC, showed desirable efficacy in the prognosis of GC patients. This model also manifested effectively in validation by using external patients' data. Conclusions: Our study developed a novel ferroptosis-related signature to predict the prognosis of gastric cancer patients. The ferroptosis-related signature had a favorable predictive ability. This model may greatly boost the treatment of GC patients in clinical practice.

Hemoglobin-to-Red Cell Distribution Width Ratio is Associated with All-Cause Mortality in Critically Ill Patients with Traumatic Brain Injury.

BACKGROUND: Hemoglobin-to-red cell distribution width ratio (HRR) has shown good prognostic value in various cancers. However, the relationship between HRR and outcomes in critically ill patients with traumatic brain injury (TBI) remains unclear. This study aimed to investigate the association between HRR and mortality among critically ill patients with TBI. METHODS: The Medical Information Mart for Intensive Care-IV (MIMIC-IV) database was utilized to conduct this retrospective cohort study. TBI patients were divided into four quartiles according to their HRR values. The primary outcome was 30-day mortality, whereas the secondary outcomes were 60-day and 120-day mortality. Univariable and multivariable Cox proportional risk models were performed to evaluate the hazard ratio (HR) and 95% confidence interval (CI) for the relationship between HRR and mortality. Receiver operating characteristic (ROC) curves were conducted to assess the prognostic value of HRR. RESULTS: For 30-day mortality, after adjustment for all potential covariates, the relationship remained significant with HRR treated as a continuous variable (HR, 95% CI: 0.87 [0.81, 0.92]; p < 0.001). In the fully adjusted model, the HR with 95% CI for the second, third, and fourth quartile groups were 0.67 (0.5, 0.9), 0.65 (0.46, 0.94), and 0.5 (0.32, 0.79), respectively, compared to the first quartile group. A similar relationship was also observed for 60-day mortality and 120-day mortality. HRR had a better predictive value than hemoglobin and red cell distribution width (RDW). CONCLUSIONS: A lower level of HRR is significantly associated with higher all-cause mortality among critically ill patients with TBI.

Identification of PTPN20 as an innate immunity-related gene in gastric cancer with Helicobacter pylori infection.

Background: Gastric cancer (GC) is among the deadliest diseases with countless incidences and deaths each year. Helicobacter pylori (Hp) is the primary type of microbe that colonizes the stomach. In recent years, increasing evidence has demonstrated that Hp infection is one of the main risk factors for GC. Elucidating the molecular mechanism of how Hp leads to GC will not only benefit the treatment of GC, but also boost the development of therapeutics for other gastric disorders caused by Hp infection. In this study, we aimed to identify innate immunity-related genes in GC and investigate their potentials as prognostic markers and therapeutic targets for Hp-related GC. Methods: Firstly, we analyzed the differentially expressed innate immunity-related genes in GC samples from the TCGA database. Then prognostic correlation analysis was carried out to explore the prognostic value of these candidate genes. By combing transcriptome data, somatic mutation data, and clinical data, co-expression analysis, functional enrichment analysis, tumor mutational burden analysis, and immune infiltration analysis were performed to reveal the pathological relevance of the candidate gene. Finally, ceRNA network was constructed to identify the genes and pathways for the regulation of the candidate gene. Results: We revealed that protein tyrosine phosphatase non-receptor type 20 (PTPN20) is a significant prognostic marker in Hp-related GC. Thus, PTPN20 levels have the potential to efficiently predict the survival of Hp-related GC patients. In addition, PTPN20 is associated with immune cell infiltration and tumor mutation burden in these GC patients. Moreover, we have also identified PTPN20-related genes, PTPN20 protein-protein interactions, and the PTPN20 ceRNA network. Conclusion: Our data suggest that PTPN20 may have critical functions in Hp-related GC. Targeting PTPN20 may be a promising way to treat Hp-related GC.

Association between obesity and short- and medium-term mortality in critically ill patients with atrial fibrillation: a retrospective cohort study.

BACKGROUND: There has been controversy about how obesity affects the clinical prognosis for patients with atrial fibrillation (AF), and the relationship between obesity and outcomes in critically ill patients with AF remains unclear. The purpose of this study was to explore the association between obesity and short- and medium-term mortality in critically ill patients with AF. METHODS: The Medical Information Mart for Intensive Care-IV (MIMIC-IV) database was used to conduct a retrospective cohort analysis on 9282 critically ill patients with AF. Patients were categorized into four groups based on their body mass index (BMI) values: underweight, normal-weight, overweight, and obese. The outcomes of this study were 30-day, 90-day, and 1-year all-cause mortality. Cox proportional-hazards models and restricted cubic spline analyses were performed to investigate the association between BMI and mortality. RESULTS: For 30-day mortality, after adjustment for all confounding factors, the hazard ratio (HR) with 95% confidence interval (CI) for the underweight, overweight, and obese categories were 1.58 (1.21, 2.07), 0.82 (0.72, 0.93), and 0.79 (0.68, 0.91), respectively, compared to the normal-weight category. Using multivariable-adjusted restricted cubic spline analysis, an "L-shaped" correlation was observed between BMI and 30-day mortality. For each 1 kg/m2 increase in BMI when BMI was less than 30 kg/m2, the risk of 30-day mortality decreased by 6.4% (HR, 95% CI: 0.936 [0.918, 0.954]; P < 0.001); however, this relationship was not present when BMI was greater than or equal to 30 kg/m2. Similar results were observed for 90-day and 1-year mortality. CONCLUSIONS: There was a nonlinear relationship between BMI and all-cause mortality among critically ill patients with AF. All-cause mortality and the BMI were negatively correlated when the BMI was less than 30 kg/m2.

Analysis of the correlation between non-alcoholic fatty liver disease and the risk of colorectal neoplasms.

This study aims at assessing the potential association between non-alcoholic fatty liver disease (NAFLD) and colorectal neoplasms (CRN). PubMed, Cochrane Library, and Embase were searched for cohort studies. 14 cohort studies with a total population of 38,761,773 were included for meta-analysis after selection. The results showed that NAFLD is related to an increased risk of CRN (OR = 1.23; 95% CI: 1.14-1.32; I2 = 70.7%, p < 0.001). In the subgroup analysis, NAFLD were found to be the independent risk factor of colorectal adenoma (CRA) (OR = 1.29; 95% CI = 1.15-1.45; I2 = 66.4%) and colorectal cancer (CRC) (OR = 1.13; 95% CI = 1.12-1.15; I2 = 69.4%). There is no close correlation between smoking status of NAFLD patients and CRN. Interestingly, bioinformatics analysis revealed that there were overlap of dysregulated gene sets among NAFLD, CRC, and two recently identified regulated cell death types, ferroptosis and cuproptosis, respectively. Our meta- and bioinformatics analysis shows that NAFLD increases the risk of CRN. Ferroptosis and cuproptosis may be the critical links between NAFLD and CRN, respectively. These findings here support that NAFLD is necessary to be considered as an emerging risk factor for CRN.

Transient B-cell depletion and regulatory T-cells mediation in combination with adenovirus mediated IGF-1 prevents and reverses autoimmune diabetes in NOD mice.

Type 1 diabetes (T1D) is one of the T cells mediated autoimmune diseases, although B cells also play an important role in the development. Both T cell and B cell targeted immunotherapies exhibited efficacies in preventing and reversing the T1D. Current study was performed to investigate the protective effects of anti-CD20/CD3 bi-specific antibody (bsAb) in combination with adenovirus mediated mouse insulin-like growth factor 1 (Adv-mIGF-1) gene on T1D in non-obese diabetes (NOD) mice. To simultaneously restore the proportion of Th cells and block the interaction of B cells as well as mediate T cell populations, the NOD model mice were randomly assigned to four groups received the saline, anti-CD20/CD3 bsAb and Adv-mIGF-1 gene alone or combination, respectively. After 16-consecutive weeks intervention, the ELISA, RT-PCR, western blot and histopathological analysis were performed to assess the pancreatic tissues and serum samples to evaluate the treatment effects. Chronic treatment of combination therapy improved T1D morbidity by improving the compartment and function of the CD4+Foxp3+ Tregs, reversing the secretion of insulin, controlling the blood glucose levels (BGLs) and alleviating insulitis as well as cell apoptosis in the NOD model mice. Moreover, current combination therapy also accelerated the proliferation and differentiation of pancreatic ß cells via suppressing the apoptosis-related factors, including caspase-3, caspase-8 and Fas, and activating the Bcl-2-related anti-apoptotic pathway. Furthermore, the cytokeratin-19 (CK-19) and pancreatic duodenal homoplasmic box-1 (PDX-1), as two important stem cell markers of pancreas were both significantly improved by treatment of combination therapy. On conclusions, chronic treatment of anti-CD20/CD3 bsAb in combination with Adv-mIGF-1 gene exerts synergistic protection on T1D in the NOD mice.

Development and validation of cuproptosis-related gene signature in the prognostic prediction of liver cancer.

Liver cancer is a generic term referring to several cancer types arising from the liver. Every year, liver cancer causes lots of deaths and other burdens to the people all over the world. Though the techniques in the diagnosis and therapy of liver cancer have undergone significant advances, the current status of treating liver cancer is not satisfactory enough. The improvement of techniques for the prognosis of liver cancer patients will be a great supplement for the treatment of liver cancer. Cuproptosis is a newly identified regulatory cell death type, which may have a close connection to liver cancer pathology. Here, we developed a prognostic model for liver cancer based on the cuproptosis-related mRNAs and lncRNAs. This model can not only effectively predict the potential survival of liver cancer patients, but also be applied to evaluate the infiltration of immune cell, tumor mutation burden, and sensitivity to anti-tumor drugs in liver cancer. In addition, this model has been successfully validated in lots of liver cancer patients' data. In summary, we wish this model can become a helpful tool for clinical use in the therapy of liver cancer.

Complete Reductive Dechlorination of 4-Hydroxy-chlorothalonil by Dehalogenimonas Populations.

Chlorothalonil (2,4,5,6-tetrachloroisophthalonitrile, TePN) is one of the most widely used fungicides all over the world. Its major environmental transformation product 4-hydroxy-chlorothalonil (4-hydroxy-2,5,6-trichloroisophthalonitrile, 4-OH-TPN) is more persistent, mobile, and toxic and is frequently detected at a higher concentration in various habitats compared to its parent compound TePN. Further microbial transformation of 4-OH-TPN has never been reported. In this study, we demonstrated that 4-OH-TPN underwent complete microbial reductive dehalogenation to 4-hydroxy-isophthalonitrile via 4-hydroxy-dichloroisophthalonitrile and 4-hydroxy-monochloroisophthalonitrile. 16S rRNA gene amplicon sequencing demonstrated that Dehalogenimonas species was enriched from 6% to 17-22% after reductive dechlorination of 77.24 µmol of 4-OH-TPN. Meanwhile, Dehalogenimonas copies increased by one order of magnitude and obtained a yield of 1.78 ± 1.47 × 108 cells per µmol Cl- released (N = 6), indicating that 4-OH-TPN served as the terminal electron acceptor for organohalide respiration of Dehalogenimonas species. A draft genome of Dehalogenimonas species was assembled through metagenomic sequencing, which harbors 30 putative reductive dehalogenase genes. Syntrophobacter, Acetobacterium, and Methanosarcina spp. were found to be the major non-dechlorinating populations in the microbial community, who might play important roles in the reductive dechlorination of 4-OH-TPN by the Dehalogenimonas species. This study first reports that Dehalogenimonas sp. can also respire on the seemingly dead-end product of TePN, paving the way to complete biotransformation of the widely present TePN and broadening the substrate spectrum of Dehalogenimonas sp. to polychlorinated hydroxy-benzonitrile.

Identification of Hub Genes in Colorectal Adenocarcinoma by Integrated Bioinformatics.

An improved understanding of the molecular mechanism of colorectal adenocarcinoma is necessary to predict the prognosis and develop new target gene therapy strategies. This study aims to identify hub genes associated with colorectal adenocarcinoma and further analyze their prognostic significance. In this study, The Cancer Genome Atlas (TCGA) COAD-READ database and the gene expression profiles of GSE25070 from the Gene Expression Omnibus were collected to explore the differentially expressed genes between colorectal adenocarcinoma and normal tissues. The weighted gene co-expression network analysis (WGCNA) and differential expression analysis identified 82 differentially co-expressed genes in the collected datasets. Enrichment analysis was applied to explore the regulated signaling pathway in colorectal adenocarcinoma. In addition, 10 hub genes were identified in the protein-protein interaction (PPI) network by using the cytoHubba plug-in of Cytoscape, where five genes were further proven to be significantly related to the survival rate. Compared with normal tissues, the expressions of the five genes were both downregulated in the GSE110224 dataset. Subsequently, the expression of the five hub genes was confirmed by the Human Protein Atlas database. Finally, we used Cox regression analysis to identify genes associated with prognosis, and a 3-gene signature (CLCA1-CLCA4-GUCA2A) was constructed to predict the prognosis of patients with colorectal cancer. In conclusion, our study revealed that the five hub genes and CLCA1-CLCA4-GUCA2A signature are highly correlated with the development of colorectal adenocarcinoma and can serve as promising prognosis factors to predict the overall survival rate of patients.

The enhanced beam sweeping algorithm for DOA estimation in the hybrid analog-digital structure with nested array.

As an emerging technology, the hybrid analog-digital structure has been considered for use in future millimeter-wave communications. Although this structure can reduce the hardware cost and power consumption considerably, the spatial covariance matrix (SCM), as the core of subspace-based direction of arrival (DOA) estimation, cannot be obtained directly. Previously, the beam sweeping algorithm (BSA) has been found effective for reconstructing the spatial covariance matrix and realizing DOA estimation by forming the beams to difference directions. However, it is computationally intractable owing to the high-dimensional matrix operation. To address this problem and improve the DOA estimation performance, this paper applies the nested array to the hybrid analog-digital structure and proposes the enhanced BSA (EBSA) for DOA estimation. By deleting a large number of redundant elements exist in the SCM to be reconstructed, the computational cost can be considerably reduced. Also, the nested array can offer high degrees of freedom. Finally, simulation experiments are conducted to verify the performance of EBSA. The results indicate that the proposed EBSA is better than the state-of-the-art method in terms of estimation accuracy and computational cost.

Cluster-Based Mutual Fund Classification and Price Prediction Using Machine Learning for Robo-Advisors.

The rise of FinTech has been meteoric in China. Investing in mutual funds through robo-advisor has become a new innovation in the wealth management industry. In recent years, machine learning, especially deep learning, has been widely used in the financial industry to solve financial problems. This paper aims to improve the accuracy and timeliness of fund classification through the use of machine learning algorithms, that is, Gaussian hybrid clustering algorithm. At the same time, a deep learning-based prediction model is implemented to predict the price movement of fund classes based on the classification results. Fund classification carried out using 3,625 Chinese mutual funds shows both accurate and efficient results. The cluster-based spatiotemporal ensemble deep learning module shows better prediction accuracy than baseline models with only access to limited data samples. The main contribution of this paper is to provide a new approach to fund classification and price movement prediction to support the decision-making of the next generation robo-advisor assisted by artificial intelligence.

Parasitic Magnetism in Magnetoelectric Antiferromagnet.

Parasitic magnetism plays an important role in magnetoelectric spin switching of antiferromagnetic oxides, but its mechanism has not been clearly investigated. Unlike the widely obtained surface boundary magnetization in magnetoelectric Cr2O3 antiferromagnet, we previously reported that Al doping could produce volume-dependent parasitic magnetism (Mpara) in Cr2O3 with the remaining magnetoelectric effect and antiferromagnetic properties. In this work, we systematically investigated the magnetic properties of Mpara in Cr2O3 through its different exchange coupling characteristics with the ferromagnet at various conditions. The columnar grain boundaries cause an antiferromagnetic sublattice breaking to produce uncompensated spins and thus are considered to be responsible for Mpara in both undoped and Al-doped Cr2O3. Finally, a model was proposed for the formation mechanism of the parasitic magnetism in Cr2O3, which explains the reported magnetic characteristics of Cr2O3, and some current topics such as the domain formation and motion in Cr2O3 during magnetoelectric spin switching. This work contributes to a deep understanding of antiferromagnetic spintronics and provides a method to realize the low-energy operation of antiferromagnetic-based magnetic random access memory.

Microbial Communities Associated with Sustained Anaerobic Reductive Dechlorination of α-, ß-, γ-, and δ-Hexachlorocyclohexane Isomers to Monochlorobenzene and Benzene.

Intensive historical and worldwide use of pesticide formulations containing hexachlorocyclohexane (HCH) has led to widespread contamination. We derived four anaerobic enrichment cultures from HCH-contaminated soil capable of sustainably dechlorinating each of α-, ß-, γ-, and δ-HCH isomers stoichiometrically to benzene and monochlorobenzene (MCB). For each isomer, the dechlorination rates, inferred from production rates of the dechlorinated products, MCB and benzene, increased progressively from <3 to ∼12 µM/day over 2 years. The molar ratio of benzene to MCB produced was a function of the substrate isomer and ranged from ß (0.77 ± 0.15), α (0.55 ± 0.09), γ (0.13 ± 0.02), to δ (0.06 ± 0.02) in accordance with pathway predictions based on prevalence of antiperiplanar geometry. Data from 16S rRNA gene amplicon sequencing and quantitative PCR revealed significant increases in the absolute abundances of Pelobacter and Dehalobacter, most notably in the α-HCH and δ-HCH cultures. Cultivation with a different HCH isomer resulted in distinct bacterial communities, but similar archaeal communities. This study provides the first direct comparison of shifts in anaerobic microbial communities induced by the dechlorination of distinct HCH isomers. It also uncovers candidate microorganisms responsible for the dechlorination of α-, ß-, γ-, and δ-HCH, a key step toward better understanding and monitoring of natural attenuation processes and improving bioremediation technologies for HCH-contaminated sites.