Impaired 2',3'-cyclic phosphate tRNA repair causes thermo-sensitive genic male sterility in rice.

Hybrid rice, widely planted in Asia, is pathogen resistant and has superior yields, making it a major contributor to global food security. The two-line hybrid rice system, which utilizes mutants exhibiting photo-/thermo-sensitive genic male sterility (P/TGMS), is the leading hybrid rice breeding technology. Mutations in THERMO-SENSITIVE GENIC MALE STERILE 5 (TMS5) accounts for over 95% of current TGMS lines. We previously found that tms5 carries a mutation in ribonuclease ZS1. Despite its importance for breeding robust rice lines, the mechanism underlying tms5-mediated TGMS remains elusive. Here, we demonstrate that TMS5 is a tRNA 2',3'-cyclic phosphatase. The tms5 mutation leads to accumulation of 2',3'-cyclic phosphate (cP)-ΔCCA-tRNAs (tRNAs without 3' CCA ended with cP), which is exacerbated by high temperatures, and reduction in the abundance of mature tRNAs, particularly alanine tRNAs (tRNA-Alas). Overexpression of tRNA-Alas in the tms5 mutant restores male fertility to 70%. Remarkably, male fertility of tms5 mutant is completely restored at high temperatures by knocking out OsVms1 which encodes the enzyme for cP-ΔCCA-tRNA generation. Our study reveals the mechanism underlying tms5-mediated TGMS in rice and provides mechanistic insight into the further improvement of TGMS in hybrid crop development.

Laser-induced plasma micromachining on surfaces parallel to the incident laser in different solutions.

Laser-induced plasma micromachining (LIPMM) is an advanced technology that utilizes the plasma generated from laser breakdown to remove material, thereby facilitating the fabrication of microstructures. This paper explores the use of LIPMM on 304 stainless steel surfaces parallel to the laser beam in different solutions, focusing on the impact of the liquid environment on the machining process. It presents a theoretical analysis of the material removal mechanisms unique to this orientation and experimentally investigates how water, a salt solution, and ethanol affect plasma shockwave characteristics. Notably, the plasma shockwave in the salt solution demonstrates the most significant peak pressure and energy, enhancing the micromachining efficiency. These findings suggest that varying the liquid environment can significantly influence LIPMM's effectiveness, offering potential improvements in precision and control. This study broadens the understanding of LIPMM applications, especially in orientations not commonly explored, and opens new possibilities for advanced micromachining techniques in various industrial applications.

Sequential glycosylations at the multibasic cleavage site of SARS-CoV-2 spike protein regulate viral activity.

The multibasic furin cleavage site at the S1/S2 boundary of the spike protein is a hallmark of SARS-CoV-2 and plays a crucial role in viral infection. However, the mechanism underlying furin activation and its regulation remain poorly understood. Here, we show that GalNAc-T3 and T7 jointly initiate clustered O-glycosylations in the furin cleavage site of the SARS-CoV-2 spike protein, which inhibit furin processing, suppress the incorporation of the spike protein into virus-like-particles and affect viral infection. Mechanistic analysis reveals that the assembly of the spike protein into virus-like particles relies on interactions between the furin-cleaved spike protein and the membrane protein of SARS-CoV-2, suggesting a possible mechanism for furin activation. Interestingly, mutations in the spike protein of the alpha and delta variants of the virus confer resistance against glycosylation by GalNAc-T3 and T7. In the omicron variant, additional mutations reverse this resistance, making the spike protein susceptible to glycosylation in vitro and sensitive to GalNAc-T3 and T7 expression in human lung cells. Our findings highlight the role of glycosylation as a defense mechanism employed by host cells against SARS-CoV-2 and shed light on the evolutionary interplay between the host and the virus.

A novel computed tomography scoring system for evaluating the risk of dural defects in anterior surgery for cervical ossification of the posterior longitudinal ligament.

OBJECTIVE: To develop and validate a computed tomography (CT)-based scoring system for evaluating the risk of dural defects (DDs) in anterior surgery for cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: We retrospectively analyzed CT imaging features of 114 OPLL patients in our institute who received anterior decompression surgery. Intraoperative DDs were found in 16 patients. A multivariable logistic regression was used to evaluate the predictors. According to the odd ratio of the included risk factors, we developed a CT scoring system for evaluating the risk of DDs in anterior OPLL surgery. The system was further validated in an independent group of 39 OPLL patients. RESULTS: We developed a CT scoring system as follows: hook sign (2 points), K-line (-) (1 point) and broad base (1 point). Thus, the system comprised 4 total points, and patients were at high risks of dural defects when the score ≥3 points. The operating characteristics of a score ≥3 for predicting DDs in the validation group were: sensitivity of 0.83, specificity of 0.94, LR positive of 13.75, LR negative of 0.18 and AUC of 0.886. The discriminatory ability of the proposed score could be demonstrated in the validation cohort. CONCLUSIONS: The relatively simple and easy-to-use scoring system we propose integrates the 3 most reliable spinal CT findings observed in patients with OPLL and a DD. The likelihood to identify the underlying risks of spinal CSF leaks may be useful to triage patients who may benefit from indirect decompression techniques.

CX-6258 hydrochloride hydrate: A potential non-nucleoside inhibitor targeting the RNA-dependent RNA polymerase of norovirus.

Human norovirus (HuNoV), a primary cause of non-bacterial gastroenteritis, currently lacks approved treatment. RdRp is vital for virus replication, making it an attractive target for therapeutic intervention. By application of structure-based virtual screening procedure, we present CX-6258 hydrochloride hydrate as a potent RdRp non-nucleoside inhibitor, effectively inhibiting HuNoV RdRp activity with an IC50 of 3.61 µM. Importantly, this compound inhibits viral replication in cell culture, with an EC50 of 0.88 µM. In vitro binding assay validate that CX-6258 hydrochloride hydrate binds to RdRp through interaction with the "B-site" binding pocket. Interestingly, CX-6258-contacting residues such as R392, Q439, and Q414 are highly conserved among major norovirus GI and GII variants, suggesting that it may be a general inhibitor of norovirus RdRp. Given that CX-6258 hydrochloride hydrate is already utilized as an orally efficacious pan-Pim kinase inhibitor, it may serve as a potential lead compound in the effort to control HuNoV infections.

Neuroimaging research progress of acupuncture treatment for patients with functional dyspepsia. / é’ˆåˆºæ²»ç–—åŠŸèƒ½æ€§æ¶ˆåŒ–ä¸è‰¯çš„ç¥žç»å½±åƒå­¦ç ”ç©¶è¿›å±•.

Neuroimaging technology provides objective and visualized research tool to study the mechanisms of acupuncture effects. Building on a systematic review of previous clinical studies on acupuncture treatment for functional dyspepsia using neuroimaging technology, this paper summarizes and synthesizes past researches from 4 aspects： acupoint-specific effects, factors influencing the effects, different physiological responses, and predictive factors for acupuncture efficacy. It suggests that acupuncture treatment for FD involves central integration with disease-targeted (acupuncture treatment can target and regulate abnormal brain functional activity patterns in patients with FD), meridian-specific (stimulation of specific acupuncture points along the stomach meridian can significantly regulate abnormal brain functional activity patterns in FD patients), and dynamic conditional features(the effects of acupuncture treatment for FD are influenced by multiple factors). Lastly, considering the current research status, this paper outlines prospects in terms of research subjects, influencing factors, and result validation, aiming to provide references for future in-depth research.

ETD-Based Proteomic Profiling Improves Arginine Methylation Identification and Reveals Novel PRMT5 Substrates.

Protein arginine methylations are important post-translational modifications (PTMs) in eukaryotes, regulating many biological processes. However, traditional collision-based mass spectrometry methods inevitably cause neutral losses of methylarginines, preventing the deep mining of biologically important sites. Herein we developed an optimized mass spectrometry workflow based on electron-transfer dissociation (ETD) with supplemental activation for proteomic profiling of arginine methylation in human cells. Using symmetric dimethylarginine (sDMA) as an example, we show that the ETD-based optimized workflow significantly improved the identification and site localization of sDMA. Quantitative proteomics identified 138 novel sDMA sites as potential PRMT5 substrates in HeLa cells. Further biochemical studies on SERBP1, a newly identified PRMT5 substrate, confirmed the coexistence of sDMA and asymmetric dimethylarginine in the central RGG/RG motif, and loss of either methylation caused increased the recruitment of SERBP1 to stress granules under oxidative stress. Overall, our optimized workflow not only enabled the identification and localization of extensive, nonoverlapping sDMA sites in human cells but also revealed novel PRMT5 substrates whose sDMA may play potentially important biological functions.

LDLR is used as a cell entry receptor by multiple alphaviruses.

Alphaviruses are arboviruses transmitted by mosquitoes and are pathogenic to humans and livestock, causing a substantial public health burden. So far, several receptors have been identified for alphavirus entry; however, they cannot explain the broad host range and tissue tropism of certain alphaviruses, such as Getah virus (GETV), indicating the existence of additional receptors. Here we identify the evolutionarily conserved low-density lipoprotein receptor (LDLR) as a new cell entry factor for GETV, Semliki Forest virus (SFV), Ross River virus (RRV) and Bebaru virus (BEBV). Ectopic expression of LDLR facilitates cellular binding and internalization of GETV, which is mediated by the interaction between the E2-E1 spike of GETV and the ligand-binding domain (LBD) of LDLR. Antibodies against LBD block GETV infection in cultured cells. In addition, the GST-LBD fusion protein inhibits GETV infection both in vitro and in vivo. Notably, we identify the key amino acids in LDLR-LBD that played a crucial role in viral entry; specific mutations in the CR4 and CR5 domain of LDLR-LBD reduce viral entry to cells by more than 20-fold. These findings suggest that targeting the LDLR-LBD could be a potential strategy for the development of antivirals against multiple alphaviruses.

Z-Selective access to α-trifluoromethyl arylenes through Pd-catalysed fluoroarylation of 1,1-difluoroallenes.

The synthesis of stereo-defined α-trifluoromethyl arylenes is of great importance in medical chemistry, organic chemistry, and materials science. However, despite the recent advances, the Z-selective formation of α-trifluoromethyl arylenes has remained underdeveloped. Here, we describe a facile approach towards Z-α-trifluoromethyl arylenes through Pd-catalysed stereoselective fluoroarylation of 1,1-difluoroallenes in the presence of a bulky monophosphine ligand.

Impacts of physiological characteristics and human activities on the species distribution models of orchids taking the Hengduan Mountains as a case.

The biogeography research of orchids through species distribution models (SDMs), a vital tool in the biogeography field, is critical to understanding the fundamental geographic distribution patterns and identifying conservation priorities. The correspondence between species occurrence and environmental information is crucial to the model's performance. However, ecological preferences unique to different orchid species, such as their life forms, are often overlooked during the modeling process. This oversight can introduce bias and increase model uncertainty. Additionally, human activities, as an important potential predictor, have not been quantified in any orchid SDMs. Taking the Hengduan Mountains as an example, we preprocessed all orchid species' occurrences based on physiological characteristics. Choosing five spatial factors related to human activities to quantify the interference and enter into models as HI factor. Using different modeling methods (GLM, MaxEnt, and RF) and evaluation indices (AUC, TSS, and Kappa), diverse modeling strategies have been constructed in the study. A double-ranking method has been adopted to select the critical orchid distribution regions. The results showed that classification models based on physiological characteristics significantly improved the model's accuracy while adding the HI factor had the same effect but the absence of enough significance. Suitability maps indicated that highly heterogeneous mountainous areas were vital for the distribution of orchids in the Hengduan Mountains. Different distribution patterns and critical regions existed between various orchid life forms geographically - terrestrial orchids were dominant in the mountain, and mycoherterophical orchids were primarily located in the north, more influenced by vegetation and temperature. Critical regions of epiphytic orchids were in the south due to a greater dependence on precipitation and temperature. These studies are informative for understanding the orchids' geographic distribution patterns in the Hengduan Mountains, promoting conservation and providing references for similar research beyond orchids.

MOV10 recruits DCP2 to decap human LINE-1 RNA by forming large cytoplasmic granules with phase separation properties.

Long interspersed element 1 (LINE-1) is the only active autonomous mobile element in the human genome. Its transposition can exert deleterious effects on the structure and function of the host genome and cause sporadic genetic diseases. Tight control of LINE-1 mobilization by the host is crucial for genetic stability. In this study, we report that MOV10 recruits the main decapping enzyme DCP2 to LINE-1 RNA and forms a complex of MOV10, DCP2, and LINE-1 RNP, exhibiting liquid-liquid phase separation (LLPS) properties. DCP2 cooperates with MOV10 to decap LINE-1 RNA, which causes degradation of LINE-1 RNA and thus reduces LINE-1 retrotransposition. We here identify DCP2 as one of the key effector proteins determining LINE-1 replication, and elucidate an LLPS mechanism that facilitates the anti-LINE-1 action of MOV10 and DCP2.

Identification of Substrates of Secreted Bacterial Protease by APEX2-Based Proximity Labeling.

The interactions between bacterial virulence factors and host receptors play a critical role during bacterial infection. Therefore, the identification of interactions between host receptor and bacterial virulence factors can not only elucidate the molecular mechanisms of bacterial infection but also provide a framework for new therapeutic and prevention strategies. Herein, we report an APEX2-based live cell proximity labeling strategy in combination with high-resolution quantitative mass spectrometry to profile the substrates of Helicobacter pylori HtrA protease on the membrane of human stomach epithelial cells. This strategy can be further applied to identify other interactions between secreted bacterial virulence factors and host receptors on live cells.

Protein-Targeted Glycan Editing on Living Cells Disrupts KRAS Signaling.

The frequent mutation of KRAS oncogene in some of the most lethal human cancers has spurred incredible efforts to develop KRAS inhibitors, yet only one covalent inhibitor for the KRASG12C mutant has been approved to date. New venues to interfere with KRAS signaling are desperately needed. Here, we report a "localized oxidation-coupling" strategy to achieve protein-specific glycan editing on living cells for disrupting KRAS signaling. This glycan remodeling method exhibits excellent protein and sugar specificity and is applicable to different donor sugars and cell types. Attachment of mannotriose to the terminal galactose/N-acetyl-D-galactosamine epitopes of integrin αv ß3 , a membrane receptor upstream of KRAS, blocks its binding to galectin-3, suppresses the activation of KRAS and downstream effectors, and mitigates KRAS-driven malignant phenotypes. Our work represents the first successful attempt to interfere with KRAS activity by manipulating membrane receptor glycosylation.

Molecular evolution of the hemoglobin gene family across vertebrates.

Adaptation to various altitudes and oxygen levels is a major aspect of vertebrate evolution. Hemoglobin is an erythrocyte protein belonging to the globin superfamily, and the α-, ß-globin genes of jawed vertebrates encode tetrameric ((α2ß2) hemoglobin, which contributes to aerobic metabolism by delivering oxygen from the respiratory exchange surfaces into cells. However, there are various gaps in knowledge regarding hemoglobin gene evolution, including patterns in cartilaginous fish and the roles of gene conversion in various taxa. Hence, we evaluated the evolutionary history of the vertebrate hemoglobin gene family by analyses of 97 species representing all classes of vertebrates. By genome-wide analyses, we extracted 879 hemoglobin sequences. Members of the hemoglobin gene family were conserved in birds and reptiles but variable in mammals, amphibians, and teleosts. Gene motifs, structures, and synteny were relatively well-conserved among vertebrates. Our results revealed that purifying selection contributed substantially to the evolution of all vertebrate hemoglobin genes, with mean dN/dS (ω) values ranging from 0.057 in teleosts to 0.359 in reptiles. In general, after the fish-specific genome duplication, the teleost hemoglobin genes showed variation in rates of evolution, and the ß-globin genes showed relatively high ω values after a gene transposition event in amniotes. We also observed that the frequency of gene conversion was high in amniotes, with fewer hemoglobin genes and higher rates of evolution. Collectively, our findings provide detail insight into complex evolutionary processes shaping the vertebrate hemoglobin gene family, involving gene duplication, gene loss, purifying selection, and gene conversion.

Comparative genomics studies on the stk gene family in vertebrates: From the bighead carp (Hypophthalmichthys nobilis) genome.

The mammalian sterile 20-like (MST) family belongs to the serine/threonine protein kinase (STK) superfamily and participates in a variety of biological processes, such as cell apoptosis, polarity, migration, immune regulation, inflammatory responses, and cancer. In the economically important bighead carp (Hypophthalmichthys nobilis), the STK gene family and immune-related biological functions may be helpful in increasing its economic yield. However, the comprehensive role of STKs in the bighead carp remains unclear. In this study, the five stk sequences from the bighead carp were divided into two classes: stk3/4 and stk24/25/26. Gene structure and motif prediction analyses confirmed that stk is conserved in the bighead carp. Compared to 26 other vertebrate species, teleosts (including bighead carp) possess more stk members because of teleost-specific whole-genome duplication. Synteny analysis revealed that stk3, stk24, stk25, and stk26 have been relatively conserved in bighead carp during evolution. Meanwhile, stk4 was lost in most Cyprinid species, including bighead carp, during evolution. RNA-seq data revealed that STK expression was associated with various pathogens, and the expression of these STKs (Hnstk3, Hnstk24a, Hnstk24b, Hnstk25, and Hnstk26) was different in seven tissues of bighead carp. In addition, we showed that STK expression levels were dramatically altered in the head kidney and that stk24 was involved in defense against Aeromonas hydrophila. This study provides a molecular basis for the analysis of stk function in bighead carp, and can be used as a reference for further phylogenomics.

Blood-brain barrier and brain structural changes in lung cancer patients with non-brain metastases.

Purpose: To explore the relationship between blood-brain barrier (BBB) leakage and brain structure in non-brain metastasis lung cancer (LC) by magnetic resonance imaging (MRI) as well as to indicate the possibility of brain metastasis (BM) occurrence. Patients and methods: MRI were performed in 75 LC patients and 29 counterpart healthy peoples (HCs). We used the Patlak pharmacokinetic model to calculate the average leakage in each brain region according to the automated anatomical labeling (AAL) atlas. The thickness of the cortex and the volumes of subcortical structures were calculated using the FreeSurfer base on Destrieux atlas. We compared the thickness of the cerebral cortex, the volumes of subcortical structures, and the leakage rates of BBB, and evaluated the relationships between these parameters. Results: Compared with HCs, the leakage rates of seven brain regions were higher in patients with advanced LC (aLC). In contrast to patients with early LC (eLC), the cortical thickness of two regions was decreased in aLCs. The volumes of twelve regions were also reduced in aLCs. Brain regions with increased BBB penetration showed negative correlations with thinner cortices and reduced subcortical structure volumes (P<0.05, R=-0.2 to -0.50). BBB penetration was positively correlated with tumor size and with levels of the tumor marker CYFRA21-1 (P<0.05, R=0.2-0.70). Conclusion: We found an increase in BBB permeability in non-BM aLCs that corresponded to a thinner cortical thickness and smaller subcortical structure volumes. With progression in LC staging, BBB shows higher permeability and may be more likely to develop into BM.

Microenvironment Created by SnSe2 Vapor and Pre-Selenization to Stabilize the Surface and Back Contact in Kesterite Solar Cells.

The ambient air-processed preparation of kesterite Cu2 ZnSn(S,Se)4 (CZTSSe) thin film is highly promising for the fabrication of low-cost and eco-friendly solar cells. However, the Sn volatilization loss and formation of a thick Mo(S,Se)2 interfacial layer during the traditional selenization process pose challenges for fabricating high-efficiency CZTSSe solar cells. Here, CZTS precursors prepared by a sol-gel process in ambient air are selenized and assisted with SnSe2 vapor via one- and two-step selenization to prepare a CZTSSe absorber on a Mo film and, subsequently, solar cells. For one-step selenization, the thickness of the fine grain and Mo(S,Se)2 layers near the back contact can be significantly reduced with increasing SnSe2 vapor partial pressure in the mixed selenization atmosphere, while the device efficiency is only 7.97% due to the severe interface recombination. For two-step selenization, the desired morphology and stoichiometry of the absorber can be achieved through the assistance of Sn-poor precursors selenized with high SnSe2 vapor partial pressure to regulate the Sn content in CZTSSe, yielding the highest efficiency of 10.85%. This study improves the understanding of the key role of the microenvironment during film growth towards the production of high-efficiency thin film solar cells and other photoelectronic devices.

Factors associated with the decision to administer ß-lactams via prolonged infusion in patients with sepsis: a prospective observational cohort study.

OBJECTIVE: ß-lactams are the most widely used antibiotics in sepsis. We aimed to explore the factors that drive physicians to choose prolonged infusion (PI) of ß-lactams in septic patients. METHODS: This prospective observational national cohort study was conducted in 40 ICUs at the teaching hospitals of 31 provinces in China between August 20, 2021 and September 20, 2021. RESULTS: Of the 441 enrolled patients, 265 (60.09%) received PI therapy. Multivariate analysis showed that multidrug-resistant bacterial infection and septic shock were independent factors associated with PI. However, our data showed that the survival benefit of PI use was evident in subgroups with less severe sepsis, including those with lower Charlson comorbidity index values (<2), those without septic shock, and those with lower acute physiology and chronic health evaluation II scores (<15). Univariate and multivariate Cox regression indicated that PI was an independent protective factor of 28d mortality, even after adjusting the variables associated with disease severity. CONCLUSIONS: PI for administering ß-lactams was not a commonly applied strategy in sepsis and was more likely to be used in severely ill patients. However, PI had a survival benefit independent of disease severity.

Is brace necessary after cervical surgery: A meta-analysis of randomized controlled trials.

BACKGROUND: Currently, there are increasing surgical treatments for neck pain. However, whether to use cervical brace after operation remains poorly defined. We aim to clear the clinical efficacy of the use of cervical brace after cervical surgery. METHODS: We searched for relevant studies in 8 electronic databases up to March 2021. The mean difference and 95% confidence intervals were used for continuous data. Cochrane Collaboration's tool was used to assess the risk of bias. The data were collected and input into the Review Manager 5.3 software (The Cochrane Collaboration, Copenhagen, Denmark). RESULTS: Four randomized controlled trials were finally included in our study. For pain, the pooled analysis showed that postoperative neck brace compared with no brace can relieve neck pain at all follow-up periods except 6 months. For neck disability index, the result showed that postoperative neck brace compared with no brace can improve neck disability index during the 3 to 12 month follow-up period. However, no significant difference was identified between 2 groups within the follow-up of 6 weeks after surgery. In addition, the result tends to get the opposite at follow-up of 24 months. For 36-Short form health survey Physical Component Summary, there was no significant difference between 2 groups in the early 3 weeks after surgery, but the results were changed after 3 weeks. For 36-short form health survey Mental Component Summary, there appears to be no significant change between 2 groups at all time intervals. CONCLUSION: Wearing a cervical brace after cervical surgery is conducive to improving symptoms after cervical surgery at different stages. However, there is no relevant evidence indicating it can improve the mental health of postoperative patients. Higher quality, large prospective randomized studies are needed to verify the current conclusions.