Atomic-level polarization in electric fields of defects for electrocatalysis.

The thriving field of atomic defect engineering towards advanced electrocatalysis relies on the critical role of electric field polarization at the atomic scale. While this is proposed theoretically, the spatial configuration, orientation, and correlation with specific catalytic properties of materials are yet to be understood. Here, by targeting monolayer MoS2 rich in atomic defects, we pioneer the direct visualization of electric field polarization of such atomic defects by combining advanced electron microscopy with differential phase contrast technology. It is revealed that the asymmetric charge distribution caused by the polarization facilitates the adsorption of H*, which originally activates the atomic defect sites for catalytic hydrogen evolution reaction (HER). Then, it has been experimentally proven that atomic-level polarization in electric fields can enhance catalytic HER activity. This work bridges the long-existing gap between the atomic defects and advanced electrocatalysis by directly revealing the angstrom-scale electric field polarization and correlating it with the as-tuned catalytic properties of materials; the methodology proposed here could also inspire future studies focusing on catalytic mechanism understanding and structure-property-performance relationship.

Building up a view and understanding of the multifunctional activity of black phosphorous nanosheet modified with the metal atom.

Constructing metal-semiconductor interfaces by loading metal atoms onto two-dimensional material to build atomically dispersed single-atom catalysts (SACs) has emerged as a new frontier for improving atom utilization and designing multifunctional electrocatalysts. Nowadays, studies on black phosphorus nanosheets in electrocatalysis have received much attention and the successful preparation of metal nanoparticle/black phosphorus (BP) hybrid electrocatalysts indicates BP nanosheets can serve as a potential support platform for SACs. Herein, by using large-scale ab initio calculations, we explored a large composition space of SACs with transition metal atoms supported on BP monolayer (M-BP) and built a comprehensive picture of activity trend, stability, and electronic origin towards oxygen reduction and evolution reaction (ORR and OER) and hydrogen evolution reaction (HER). The results show that the catalytic activity can be widely tuned by reasonable regulation of metal atoms. Ni-, Pd-, and Pt-BP could effectively balance the binding strength of the target intermediates, thus achieving efficient bifunctional activity for OER and ORR. Favorable bifunctional catalytic performance for OER and HER can be realized on Rh-BP. Especially, Pt-BP exhibits promising trifunctional activity towards OER, ORR, and HER. Multiple-level corrections among overpotential, Gibbs free energy, orbital population, and d-band center reveal that the trend and origin of catalytic activity are intrinsically determined by the d-band center of metal sites. The thermodynamic and dynamic stability simulations demonstrate that the active metal centers are firmly anchored on BP substrate with intact M-P bonds. These findings provide a theoretical basis for the rational design of BP-based SACs toward promising multifunctional activity.

Immune-related gene IL17RA as a diagnostic marker in osteoporosis.

Objectives: Bone immune disorders are major contributors to osteoporosis development. This study aims to identify potential diagnostic markers and molecular targets for osteoporosis treatment from an immunological perspective. Method: We downloaded dataset GSE56116 from the Gene Expression Omnibus database, and identified differentially expressed genes (DEGs) between normal and osteoporosis groups. Subsequently, differentially expressed immune-related genes (DEIRGs) were identified, and a functional enrichment analysis was performed. A protein-protein interaction network was also constructed based on data from STRING database to identify hub genes. Following external validation using an additional dataset (GSE35959), effective biomarkers were confirmed using RT-qPCR and immunohistochemical (IHC) staining. ROC curves were constructed to validate the diagnostic values of the identified biomarkers. Finally, a ceRNA and a transcription factor network was constructed, and a Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis was performed to explore the biological functions of these diagnostic markers. Results: In total, 307 and 31 DEGs and DEIRGs were identified, respectively. The enrichment analysis revealed that the DEIRGs are mainly associated with Gene Ontology terms of positive regulation of MAPK cascade, granulocyte chemotaxis, and cytokine receptor. protein-protein interaction network analysis revealed 10 hub genes: FGF8, KL, CCL3, FGF4, IL9, FGF9, BMP7, IL17RA, IL12RB2, CD40LG. The expression level of IL17RA was also found to be significantly high. RT-qPCR and immunohistochemical results showed that the expression of IL17RA was significantly higher in osteoporosis patients compared to the normal group, as evidenced by the area under the curve Area Under Curve of 0.802. Then, we constructed NEAT1-hsa-miR-128-3p-IL17RA, and SNHG1-hsa-miR-128-3p-IL17RA ceRNA networks in addition to ERF-IL17RA, IRF8-IL17RA, POLR2A-IL17RA and ERG-IL17RA transcriptional networks. Finally, functional enrichment analysis revealed that IL17RA was involved in the development and progression of osteoporosis by regulating local immune and inflammatory processes in bone tissue. Conclusion: This study identifies the immune-related gene IL17RA as a diagnostic marker of osteoporosis from an immunological perspective, and provides insight into its biological function.

Understanding the Activity and Design Principle of Dual-Atom Catalysts Supported on C2N for Oxygen Reduction and Evolution Reactions: From Homonuclear to Heteronuclear.

Using large-scale ab initio calculations and taking the two-dimensional C2N monolayer as a substrate, we sampled a large combinatorial space of C2N-supported homonuclear and heteronuclear dual-atom catalysts and built a detailed view of catalytic activity and stability toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The results indicate that regulating combinations of metal pairs could widely tune the catalytic performance. Pd2-, Pt2-, and PdPt-C2N could effectively balance the adsorption strength of intermediates and achieve optimal bifunctional activity. The favorable catalytic performance could also be realized on GaPd-C2N for the ORR and PdRh-C2N for the OER, surpassing corresponding homonuclear counterparts. The thermodynamic and electrochemical stability simulations reveal that these metal pairs can be stably anchored onto the C2N matrix. Multiple-level descriptors, including Gibbs free energy, d-band center, and bonding/antibonding orbital population, are established to track the activity trend and reveal the origin of activity, indicating that catalytic activity is intrinsically governed by the d-band center of metal pairs.

Fast carrier diffusion via synergistic effects between lithium-ions and polarons in rutile TiO2.

Carrier mobility in titanium dioxide (TiO2) systems is a key factor for their application as energy materials, especially in solar cells and lithium-ion batteries. Studies on the diffusion of Li-ions and polarons in rutile TiO2 systems have attracted extensive attention. However, how their interaction affects the diffusion of Li-ions and electron polarons is largely unclear and related studies are relatively lacking. By using first-principles calculations, we systematically investigate the interaction between the intercalated Li-ions and electron polarons in rutile TiO2 materials. Our analysis shows that the diffusion barrier of the electron polarons decreases around the Li-ion. The interaction between the Li-ions and polarons would benefit their synergistic diffusion both in the pristine and defective rutile TiO2 systems. Our study reveals the synergistic effects between the ions and polarons, which is important for understanding the carrier properties in TiO2 systems and in further improving the performance of energy materials.

Effects of moxibustion on serum levels of β-EP, SP and expression of IL-1β and COX-2 protein in brainstem in rats with migraine / 中国针灸

OBJECTIVE@#To observe the effects of moxibustion at "Baihui" (GV 20) and "Dazhui" (GV 14) at different time points on the serum level of β-endorphin (β-EP), substance P (SP) and expression of interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2) protein in brainstem in rats with migraine, and to explore the effect and mechanism of moxibustion in preventing and treating migraine.@*METHODS@#Forty male SD rats were randomly divided into a blank group, a model group, a prevention+treatment (PT) group and a treatment group, 10 rats in each group. Except the blank group, the rats in the remaining groups were injected with nitroglycerin subcutaneously to prepare migraine model. The rats in the PT group were treated with moxibustion 7 days before modeling (once a day) and 30 min after modeling, while the rats in the treatment group were treated with moxibustion 30 min after modeling. The "Baihui" (GV 20) and "Dazhui" (GV 14) were taken for 30 minutes each time. The behavioral scores in each group were observed before and after modeling. After intervention, ELISA method was used to detect the serum level of β-EP and SP; the immunohistochemistry method was used to detect the number of positive cells of IL-1β in brainstem; the Western blot method was used to detect the expression of COX-2 protein in brainstem.@*RESULTS@#Compared with the blank group, the behavioral scores in the model group were increased 0-30 min, 60-90 min and 90-120 min after modeling (P<0.01); compared with the model group, in the treatment group and the PT group, the behavioral scores were decreased 60-90 min and 90-120 min after modeling (P<0.01). Compared with the blank group, in the model group, the serum level of β-EP was decreased (P<0.01), while the serum level of SP, the number of positive cells of IL-1β in brainstem and the expression of COX-2 protein were increased (P<0.01). Compared with the model group, in the PT group and and the treatment group, the serum level of β-EP was increased (P<0.01), while the serum level of SP, the number of positive cells of IL-1β and the expression of COX-2 protein in brainstem were decreased (P<0.01, P<0.05). Compared with the treatment group, in the PT group, the serum level of β-EP was increased and COX-2 protein expression was decreased (P<0.05).@*CONCLUSION@#Moxibustion could effectively relieve migraine. The mechanism may be related to reduce the serum level of SP, IL-1β and COX-2 protein expression in brainstem, and increase the serum level of β-EP, and the optimal effect is observed in the PT group.

Comprehensive analysis of senescence-related genes and immune infiltration in intervertebral disc degeneration: a meta-data approach utilizing bulk and single-cell RNA sequencing data.

Objectives: This study aims to identify the key senescence genes and potential regulatory mechanisms that contribute to the etiology of intervertebral disc degeneration (IDD). Method: We analyzed GSE34095 and GSE70362 datasets, identifying key senescence-related differentially expressed genes (DEGs) in IDD using lasso regression. Risk scores classified patients into high- and low-risk groups. We compared pathways, functions, and immune infiltration between these groups. Diagnostic ability was assessed using ROC curves and a nomogram predicted IDD incidence. In single-cell dataset GSE165722, we evaluated expression of key senescence-related DEGs. Results: We identified 12 key senescence-related DEGs distinguishing high- and low-risk IDD patients. Enrichment analysis revealed cellular stress response, apoptotic signaling pathway, and protein kinase activation differences. Immune cell analysis showed elevated eosinophils in low-risk group and increased effector memory CD8 T, central memory CD4 T, myeloid-derived suppressor, natural killer, monocyte, Type 1 T helper, plasmacytoid dendritic, and natural killer T cells in high-risk group. A nomogram using AUC >0.75 genes (CXCL8, MAP4K4, MINK1, and TNIK) predicted IDD incidence with good diagnostic power. High senescence scores were observed in neutrophils. Conclusion: Our diagnostic model, based on key senescence-related DEGs and immune cell infiltration, offers new insights into IDD pathogenesis and immunotherapy strategies.

Nuclear Quantum Effects on the Charge-Density Wave Transition in NbX2 (X = S, Se).

Understanding the origin of charge-density wave (CDW) instability is important for manipulating novel collective electronic states. Many layered transition metal dichalcogenides (TMDs) share similarity in the structural and electronic instability, giving rise to diverse CDW phases and superconductivity. It is still puzzling that even isostructural and isoelectronic TMDs show distinct CDW features. For instance, bulk NbSe2 exhibits CDW order at low temperature, while bulk NbS2 displays no CDW instability. The CDW transitions in single-layer NbS2 and NbSe2 are also different. In the classic limit, we investigate the electron correlation effects on the dimensionality dependence of the CDW ordering. By performing ab initio path integral molecular dynamics simulations and comparative analyses, we further revealed significant nuclear quantum effects in these systems. Specifically, the quantum motion of sulfur anions significantly reduces the CDW transition temperature in both bulk and single-layer NbS2, resulting in distinct CDW features in the NbS2 and NbSe2 systems.

Transcriptome research identifies four hub genes related to primary myelofibrosis: a holistic research by weighted gene co-expression network analysis.

OBJECTIVES: This study aimed to identify specific diagnostic as well as predictive targets of primary myelofibrosis (PMF). METHODS: The gene expression profiles of GSE26049 were obtained from Gene Expression Omnibus (GEO) dataset, WGCNA was constructed to identify the most related module of PMF. Subsequently, Gene Ontology (GO), Kyoto Encyclopedia Genes and Genomes (KEGG), Gene Set Enrichment Analysis (GSEA) and Protein-Protein interaction (PPI) network were conducted to fully understand the detailed information of the interested green module. Machine learning, Principal component analysis (PCA), and expression pattern analysis including immunohistochemistry and immunofluorescence of genes and proteins were performed to validate the reliability of these hub genes. RESULTS: Green module was strongly correlated with PMF disease after WGCNA analysis. 20 genes in green module were identified as hub genes responsible for the progression of PMF. GO, KEGG revealed that these hub genes were primarily enriched in erythrocyte differentiation, transcription factor binding, hemoglobin complex, transcription factor complex and cell cycle, etc. Among them, EPB42, CALR, SLC4A1 and MPL had the most correlations with PMF. Machine learning, Principal component analysis (PCA), and expression pattern analysis proved the results in this study. CONCLUSIONS: EPB42, CALR, SLC4A1 and MPL were significantly highly expressed in PMF samples. These four genes may be considered as candidate prognostic biomarkers and potential therapeutic targets for early stage of PMF. The effects are worth expected whether in the diagnosis at early stage or as therapeutic target.

Tuning the Electrocatalytic Properties of Black and Gray Arsenene by Introducing Heteroatoms.

On the basis of density functional theory calculations, we explored the catalytic properties of various heteroatom-doped black and gray arsenene toward the oxygen reduction reaction (ORR), the oxygen evolution reaction (OER), and the hydrogen evolution reaction (HER). The calculation results show that pristine black (b-As) and gray arsenene (g-As) exhibit poor catalytic performance because of too weak intermediate adsorption. Heteroatom doping plays a key role in optimizing catalytic performance. Among the candidate dopants O, C, P, S, and Sb, O is the most promising one used in arsenene to improve the ORR and OER catalytic performance. Embedding O atoms could widely tune the binding strength of reactive intermediates and improve the catalytic activity. Single O-doped g-AsO 1 can achieve efficient bifunctional activity for both the OER and the ORR with optimal potential gap. b-AsO 1 and b-AsO 2 exhibit the optimal OER and ORR catalytic performance, respectively. For the HER, double C-doped g-AsC 2 could tune the adsorption of hydrogen to an optimal value and significantly enhance the catalytic performance. These findings indicate that arsenene could provide a new platform to explore high-efficiency electrocatalysts.

Exosome Transplantation From Patients With Schizophrenia Causes Schizophrenia-Relevant Behaviors in Mice: An Integrative Multi-omics Data Analysis.

Exosomes are involved in the pathophysiology of neuropsychiatric diseases, but the role of exosomes in schizophrenia (SCZ) is unclear. Here, we demonstrate that transplantation of serum exosomes from SCZ patients into mice caused behavioral abnormalities such as deficits in prepulse inhibition and sociability, hyperactivity, and anxiogenesis. A comparative bioinformatics analysis suggested shared and distinct differentially expressed genes (DEGs) and enriched molecular pathways in the brains of SCZ exosome-recipient mice, methylazoxymethanol acetate-treated rats, and SCZ patients, which correlates evidence of altered prefrontal-hippocampal functional coherence in SCZ. A large proportion of SCZ-relevant DEGs in the exosome-recipient mice were targets of DE exosomal miRNAs in SCZ patients. Furthermore, we identified 20 hub genes for SCZ risk genes, including BDNF and NRG1, which were DE miRNA targets in SCZ. Collectively, our study suggests that SCZ exosome transplantation caused SCZ-relevant behaviors in mice, and epigenetic regulation may contribute to the phenotypes in the SCZ exosome-recipient mice. Our results may provide a potential animal model and novel therapeutic targets for SCZ.

Skeletal Muscle Metabolomic Responses to Endurance and Resistance Training in Rats under Chronic Unpredictable Mild Stress.

The objectives of this study were to compare the antidepressant effects between endurance and resistance exercise for optimizing interventions and examine the metabolomic changes in different types of skeletal muscles in response to the exercise, using a rat model of chronic unpredictable mild stress (CUMS)-induced depression. There were 32 male Sprague-Dawley rats randomly divided into a control group (C) and 3 experimental groups: CUMS control (D), endurance exercise (E), and resistance exercise (R). Group E underwent 30 min treadmill running, and group R performed 8 rounds of ladder climbing, 5 sessions per week for 4 weeks. Body weight, sucrose preference, and open field tests were performed pre and post the intervention period for changes in depressant symptoms, and the gastrocnemius and soleus muscles were sampled after the intervention for metabolomic analysis using the 1H-NMR technique. The results showed that both types of exercise effectively improved the depression-like symptoms, and the endurance exercise appeared to have a better effect. The levels of 10 metabolites from the gastrocnemius and 13 metabolites from the soleus of group D were found to be significantly different from that of group C, and both types of exercise had a callback effect on these metabolites, indicating that a number of metabolic pathways were involved in the depression and responded to the exercise interventions.

Anti-infection effect of phage and its clinical application / 中华危重病急救医学

In recent years, the problem of bacterial resistance has become more and more serious, which has brought troubles to global public health and medical care. The time and money required to develop new antibiotics is even greater than before. Bacteriophage is a kind of virus that can specifically infect bacteria, fungi, actinomycetes and other microorganisms. Relying on host bacteria to replicate in large numbers, rich species, low research and development cost, the value of anti-infection therapy is very considerable. It is a new generation of biological antimicrobial agents with great potential. This paper briefly describes the sterilization mechanism, progress of research on anti-infection aspect and clinical application of phage, in order to provide reference for phage anti-infection treatment and clinical application.

Seamlessly Splicing Metallic Sn x Mo1- x S2 at MoS2 Edge for Enhanced Photoelectrocatalytic Performance in Microreactor.

Accurate design of the 2D metal-semiconductor (M-S) heterostructure via the covalent combination of appropriate metallic and semiconducting materials is urgently needed for fabricating high-performance nanodevices and enhancing catalytic performance. Hence, the lateral epitaxial growth of M-S Sn x Mo1- x S2/MoS2 heterostructure is precisely prepared with in situ growth of metallic Sn x Mo1- x S2 by doping Sn atoms at semiconductor MoS2 edge via one-step chemical vapor deposition. The atomically sharp interface of this heterostructure exhibits clearly distinguished performance based on a series of characterizations. The oxygen evolution photoelectrocatalytic performance of the epitaxial M-S heterostructure is 2.5 times higher than that of pure MoS2 in microreactor, attributed to the efficient electron-hole separation and rapid charge transfer. This growth method provides a general strategy for fabricating seamless M-S lateral heterostructures by controllable doping heteroatoms. The M-S heterostructures show increased carrier migration rate and eliminated Fermi level pinning effect, contributing to their potential in devices and catalytic system.

Ab initio study of the miscibility for solid hydrogen-helium mixtures at high pressure.

Understanding the behavior of H2-He binary mixtures at high pressure is of great importance. Two more recent experiments [J. Lim and C. S. Yoo, Phys. Rev. Lett. 120, 165301 (2018) and R. Turnbull et al., ibid. 121, 195702 (2018)] are in conflict, regarding the miscibility between H2 and He in solids at high pressure. On the basis of first-principles calculations combined with the structure prediction method, we investigate the miscibility for solid H2-He mixtures at pressures from 0 GPa to 200 GPa. It is found that there is no sign of miscibility and chemical reactivity in H2-He mixtures with any H:He ratio. Moreover, instead of H2-He mixtures, the calculated Raman modes of the N-H mixtures can better explain the characteristic peaks observed experimentally, which were claimed to be the H-He vibrational modes. These calculation results are more in line with the experimental findings by Turnbull et al. [Phys. Rev. Lett. 121, 195702 (2018)].

Chemically modified phosphorene as efficient catalyst for hydrogen evolution reaction.

Hydrogen gas produced by electrolysis has been considered as an excellent alternative to fossil fuels. Developing non-noble metal catalysts with high electrocatalytic activities is an effective way to reduce the cost of hydrogen production. Recently, black phosphorus (BP) based materials have been reported to have good potential as electrocatalysts for hydrogen evolution reaction (HER). Herein, we systematically study the catalytic performance of monolayer BP (phosphorene) and several chemically modified phosphorenes (N/S/C/O doping and adsorbed NH2/OH functional groups) for HER on the basis of first-principles calculations. For pristine phosphorene, the armchair edge shows much better catalytic activity than the plane site and zigzag edge. The electronic states of phosphorene near the Fermi level are strongly influenced by chemical modifications. Both of doping heteroatoms into the lattice and introducing NH2/OH functional groups can effectively improve the catalytic performance of the plane site and zigzag edge site, but slightly degrade the armchair edge. These theoretical results shed light on the microscopic understanding of the active sites in BP based electrocatalysts for HER and pave the way for further improving their catalytic performance.

Establishment and application of intelligent document management system for nursing system / 中国实用护理杂志

Objective:To establish and apply an intelligent nursing system document management system to provide bedside guidance for clinical nurses and standardize clinical nursing services.Methods:The intelligent nursing system document management system was established and successfully applied in clinical practice. Its functions included upload management, intelligent retrieval, cross-specialty sharing, multi-terminal access, reading trace management, individualized document revision reminder and file validity management. The problem of time-consuming file management, file retrieval time, and problem occurrence rate in file management when collecting manual management paper system files and intelligent system management electronic system files was evaluated, and the application effect of the intelligent nursing system file management system was evaluated.Results:The average time taken by the file administrator to collect and recycle documents was (492.68±14.04) min and (195.43±8.12) min. After the system was established, the files could be updated and discarded directly on the computer, which saved the time of collection and collection. The time consumption of the document decreased from (82.72±7.47) s to (44.75±5.28) s, the difference was statistically significant ( t value was 34.242, P<0.01); the average incidence of dysfunction in the ward was 2.78%, and the average rate of inconsistent version was 5.56%. After that, the files were managed uniformly and synchronized, eliminating the lack of files and inconsistent versions; there was no need to print paper documents, which significantly reduced the cost of consumables. Conclusion:Through the establishment and application of the intelligent nursing system document management system, the document management process was rationally optimized, the accuracy and convenience of document use were effectively improved, the manpower and consumables cost of document management were reduced, and the efficiency and quality of document management were improved.

Synergy of tellurium and defects in control of activity of phosphorene for oxygen evolution and reduction reactions.

Developing low-cost and metal-free electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is desirable for renewable energy technologies. Recent experiments show that tellurium (Te) atoms can be effectively doped into black phosphorus (BP) nanosheets, and they greatly improve its OER catalytic performance. However, the specific active sites and microscopic configurations in the atomic-scale are still ambiguous. Here, we show that the doped Te atoms prefer to bond with each other to form clusters in phosphorene and they can be further stabilized by various intrinsic defects (Stone-Wales, single vacancy defects and zigzag nanoribbon). Benefiting from the reduced binding strength of O*, Te dopants and intrinsic defects synergistically boost the catalytic activity of phosphorene. The best OER catalytic activity could be realized in the cluster SW2-Te1p (Stone-Wales defect decorated by one Te atom). For ORR, the cluster Pri-Te3p (pristine phosphorene decorated by three Te atoms) exhibits optimal catalytic activity. Calculated ORR/OER potential gaps indicate that the SW2-Te3p cluster most likely acts as the efficient bifunctional catalytic site for both ORR and OER.

Doping single transition metal atom into PtTe sheet for catalyzing nitrogen reduction and hydrogen evolution reactions.

We systematically explored the catalytic performance of a novel two dimensional material PtTe sheet for nitrogen reduction reaction (NRR) and hydrogen evolution reaction (HER) by using first-principles calculation. Although pristine PtTe shows poor NRR and HER activity, doping transition metal (TM) atoms into the lattice could effectively enhance the catalytic performance. Calculations show that four TM doped structures, including W-Pt18Te17, Ru-Pt18Te17, Mo-Pt18Te17, and Cr-Pt18Te17, are promising NRR catalysts on the prerequisite of whose HER activities are effectively suppressed. Moreover, the HER performance of the PtTe sheet could also be significantly improved with introduced TM atoms. In particular, Cu, Cr, Co, Ni, Mo, Rh, Ru, and Tc atoms supported by the PtTe sheet with Te-vacancy are promising HER electrocatalysts. The improved HER performance is attributed to the reduced adsorption free energy of the H atom. Both the doped TM atoms and the adjacent Pt atoms are effective active sites. Among all considered structures, Mo-, Cr-, and Ru-Pt18Te17 sheets boost catalytic activity for both NRR and HER. This study provides new design strategies to enhance the catalytic performance of the PtTe sheet for the NRR/HER.

Shape-Engineered Synthesis of Atomically Thin 1T-SnS2 Catalyzed by Potassium Halides.

Shape engineering plays a crucial role in the application of two-dimensional (2D) layered metal dichalcogenide (LMD) crystalline materials in terms of physical and chemical property modulation. However, controllable growth of 1T phase tin disulfide (SnS2) with multifarious morphologies has rarely been reported and remains challenging. Herein, we report a direct synthesis of large-size, uniform, and atomically thin 1T-SnS2 with multiple morphologies by adding potassium halides via a facile chemical vapor deposition process. A variety of morphologies, i.e., from hexagon, triangle, windmill, and dendritic to coralloid, corresponding to fractal dimensions from 1.01 to 1.81 are accurately controlled by growth conditions. Moreover, the Sn concentration controls the morphology change of SnS2. The edge length of the SnS2 dendritic flake can grow larger than 500 µm in 5 min. Potassium halides can significantly reduce the surface migration barrier of the SnS2 cluster and enhance the SnS2 adhesion force with substrate to facilitate efficient high in-plane growth of monolayer SnS2 compared to sodium halides by density functional theory calculations. More branched SnS2 with higher fractal dimension provides more active sites for enhancing hydrogen evolution reactions. Importantly, we prove that potassium halides are preferable for 1T-phase LMDs structures, while sodium halides are more suitable for 2H-phase materials. The growth mechanism proposed here provides a general approach for controllable-phase synthesis of 2D LMD crystals and related heterostructures. Shape engineering of 2D materials also provides a strategy to tune LMD properties for demanding applications.