Depletion Strategies for Crystallized Layers of Two-Dimensional Nanosheets to Enhance Lithium-Ion Conductivity in Polymer Nanocomposites.

The assembly of long-range aligned structures of two-dimensional nanosheets (2DNSs) in polymer nanocomposites (PNCs) is in urgent need for the design of nanoelectronics and lightweight energy-storage materials of high conductivity for electricity or heat. These 2DNS are thin and exhibit thermal fluctuations, leading to an intricate interplay with polymers in which entropic effects can be exploited to facilitate a range of different assemblies. In molecular dynamics simulations of experimentally studied 2DNSs, we show that the layer-forming crystallization of 2DNSs is programmable by regulating the strengths and ranges of polymer-induced entropic depletion attractions between pairs of 2DNSs, as well as between single 2DNSs and a substrate surface, by exclusively tuning the temperature and size of the 2DNS. Enhancing the temperature supports the 2DNS-substrate depletion rather than crystallization of 2DNSs in the bulk, leading to crystallized layers of 2DNSs on the substrate surfaces. On the other hand, the interaction range of the 2DNS-2DNS depletion attraction extends further than the 2DNS-substrate attraction whenever the 2DNS size is well above the correlation length of the polymers, which results in a nonmonotonic dependence of the crystallization layer on the 2DNS size. It is demonstrated that the depletion-tuned crystallization layers of 2DNSs contribute to a conductive channel in which individual lithium ions (Li ions) migrate efficiently through the PNCs. This work provides statistical and dynamical insights into the balance between the 2DNS-2DNS and 2DNS-substrate depletion interactions in polymer-2DNS composites and highlights the possibilities to exploit depletion strategies in order to engineer crystallization processes of 2DNSs and thus to control electrical conductivity.

Clinical Outcome Analysis of Robot-Assisted Pedicle Screw Insertion in the Treatment of Ankylosing Spondylitis Complicated with Spinal Fractures.

BACKGROUND: Vague spinal anatomical landmarks in patients with ankylosing spondylitis (AS) make intraoperative insertion of pedicle screws difficult under direct vision. Currently, the clinical outcome is significantly improved with robot guidance. This study aims to explore the efficacy of robot-assisted pedicle screw insertion in treating AS combined with spinal fractures. METHODS: Forty patients (341 screws) who underwent pedicle screw insertion with AS complicated with spinal fractures were included. According to different surgical methods, 16 patients (135 screws) were classified into the robot group and 24 (206 screws) into the free-hand group. Intraoperative blood loss, operative duration, and adverse events were compared between the 2 groups. Gertzbein and Robbins classification was used to classify the accuracy of screw position. Clinical outcomes were evaluated by Visual Analog Scale, Japanese Orthopedic Association, and Oswestry Disability Index. RESULTS: No statistically significant differences between baseline data of the groups. The difference in the blood loss between groups wasn't significant, nor was the operative duration. No severe adverse events related to pedicle screw insertion were reported in either group. Notably, the accuracy of screw insertion was significantly higher in the robot group (129/135) than in the free-hand group (182/206). The lateral perforation prevalence didn't differ among groups. Visual Analog Scale in the third month postoperatively was lower in the robot group than in the free-hand group, with a significant difference. CONCLUSIONS: The study demonstrates statistically superior accuracy and surgical outcome of robot-assisted pedicle screw insertion in the treatment of AS complicated with spinal fractures compared with the traditional free-hand operation.

Erythrocyte membrane-coated nanocarriers modified by TGN for Alzheimer's disease.

Alzheimer's disease (AD) is an aging-related neurodegenerative disease, and the main pathological feature was ß-amyloid protein (Aß) deposition. Recently, bioactive materials-based drug delivery system has been widely investigated for the treatment of AD. In this study, we developed a red blood cells (RBC) membrane-coated polycaprolactone (PCL) nanoparticles (NPs) loading with a therapeutic agent for AD, curcumin (Cur). A functional peptide TGNYKALHPHN (TGN) was conjugated to the surface of membrane for blood-brain barrier (BBB) transport (TGN-RBC-NPs-Cur). TGN peptide can be recognized by receptors on the BBB and has great potential for brain transport. To confirm the targeted delivery of Cur to the brain, a cell co-culturing immortalized human cerebral microvascular endothelial cells and human brain astrocytes glioblastoma (hCMEC/D3 and U-118MG) in vitro model was established. As a result, the BBB transporting ratio of TGN-RBC-NPs-FITC was 29.64% at 12 h which was approximately eight-fold than RBC-NPs-FITC. The improvement of drug accumulation in the AD lesion was confirmed by the NPs modified with the BBB-penetrating peptide in the fluorescence imaging and quantitative analysis with UPLC-MS/MS in vivo. The neuroprotective effects were evaluated with new object recognition behavioral test, in vitro AD cell model, dendritic spine stain, GFAP and IBA1 immunofluorescence stain. The spatial learning and memory abilities of the AD model mice treated with TGN-RBC-NPs-Cur were obviously enhanced compared with the AD control mice and were also better than Cur at the same dosage. These results were consistent with the values of protection index of rat adrenal pheochromocytoma cells (PC12 cells) treated by Aß25-35. TGN-RBC-NPs-Cur increased the dendritic segments densities and restrained activation of microglia and astrocytes of AD mice, as well as reversed cognitive function of AD mice. All of the results demonstrated TGN-RBC-NPs-Cur a promising therapeutic strategy for delaying the progression of AD by designing biomimetic nanosystems to deliver drugs into the brain.

Combination of Backbone Rigidity and Richness in Aryl Structures Enables Direct Membrane Translocation of Polymer Scaffolds for Efficient Gene Delivery.

The development of cell-penetrating polymers with endocytosis-independent cell uptake pathways has emerged as a prominent strategy to enhance the transfection efficiency. Inspired by the rigid α-helical structure that endows polypeptides with cell-penetrating ability, we propose that a rigid backbone can facilitate the corresponding polymer vector's performance in gene delivery by bypassing the difficult endosomal escape process. Meanwhile, the installation of aromatic domains, as a way to promote gene transfection efficiency, is employed through the construction of a poly(benzyl ether) (PBE)-based scaffold in this work. We demonstrate that the direct membrane translocation capability of the synthesized PBE contributes to its enhanced transfection performance and excellent biocompatibility profile, rendering the imidazolium-functionalized PBE scaffold with higher activity and biocompatibility. Molecular details of the PBE-lipid interaction are also revealed in molecular dynamics simulations, indicating the important roles of individual structural elements on the polymeric scaffold in the membrane penetration process.

[Serum metabolomics study of Psoraleae Fructus in improving learning and memory ability of APP/PS1 mice].

This study aimed to investigate the mechanism of Psoraleae Fructus in improving the learning and memory ability of APP/PS1 mice by serum metabolomics, screen the differential metabolites of Psoraleae Fructus on APP/PS1 mice, and reveal its influence on the metabolic pathway of APP/PS1 mice. Thirty 3-month-old APP/PS1 mice were randomly divided into a model group and a Psoraleae Fructus extract group, and another 15 C57BL/6 mice of the same age were assigned to the blank group. The learning and memory ability of mice was evaluated by the Morris water maze and novel object recognition tests, and metabolomics was used to analyze the metabolites in mouse serum. The results of the Morris water maze test showed that Psoraleae Fructus shortened the escape latency of APP/PS1 mice(P<0.01), and increased the number of platform crossing and residence time in the target quadrant(P<0.01). The results of the novel object recognition test showed that Psoraleae Fructus could improve the novel object recognition index of APP/PS1 mice(P<0.01). Eighteen differential metabolites in serum were screened out by metabolomics, among which the levels of arachidonic acid, tryptophan, and glycerophospholipid decreased after drug administration, while the levels of glutamyltyrosine increased after drug administration. The metabolic pathways involved included arachidonic acid metabolism, glycerophospholipid metabolism, tryptophan metabolism, linoleic acid metabolism, α-linolenic acid metabolism, and glycerolipid metabolism. Therefore, Psoraleae Fructus can improve the learning and memory ability of APP/PS1 mice, and its mechanism may be related to the effects in promoting energy metabolism, reducing oxidative damage, protecting central nervous system, reducing neuroinflammation, and reducing Aß deposition. This study is expected to provide references for Psoraleae Fructus in the treatment of Alzheimer's disease(AD) and further explain the mechanism of Psoraleae Fructus in the treatment of AD.

[Mechanism of albiflorin in improvement of Alzheimer's disease based on network pharmacology and in vitro experiments].

This study aimed to explore the mechanism of albiflorin in the treatment of Alzheimer's disease(AD) based on network pharmacology, molecular docking, and in vitro experiments. Network pharmacology was used to predict the potential targets and pathways of albiflorin against AD, and molecular docking technology was used to verify the binding affinity of albiflorin to key target proteins. Finally, the AD cell model was induced by Aß_(25-35) in rat pheochromocytoma(PC12) cells and intervened by albiflorin to validate core targets and pathways. The results of network pharmacological analysis showed that albiflorin acted on key targets such as mitogen-activated protein kinase-1(MAPK1 or ERK2), albumin(ALB), epidermal growth factor receptor(EGFR), caspase-3(CASP3), and sodium-dependent serotonin transporter(SLC6A4), and signaling pathways such as MAPK, cAMP, and cGMP-PKG. The results of molecular docking showed that albiflorin had strong binding affinity to MAPK1(ERK2). In vitro experiments showed that compared with the blank group, the model group showed decreased cell viability, decreased expression level of B-cell lymphoma 2(Bcl-2), increased Bcl-2-associated X protein(Bax), and reduced phosphorylation level of extracellular signal-regulated kinase 1/2(ERK1/2) and the relative expression ratio of p-ERK1/2 to ERK1/2. Compared with the model group, the albiflorin group showed potentiated cell viability, up-regulated expression of Bcl-2, down-regulated Bax, and increased phosphorylation level of ERK1/2 and the relative expression ratio of p-ERK1/2 to ERK1/2. These results suggest that the mechanism of albiflorin against AD may be related to its activation of the MAPK/ERK signaling pathway and its inhibition of neuronal apoptosis.

Effect of Nanoscale in Situ Interface Welding on the Macroscale Thermal Conductivity of Insulating Epoxy Composites: A Multiscale Simulation Investigation.

Insulating thermally conductive polymer composites are in great demand in integrated-circuit packages, for efficient heat dissipation and to alleviative short-circuit risk. Herein, the continuous oriented hexagonal boron nitride (h-BN) frameworks (o-BN@SiC) were prepared via self-assembly and in situ chemical vapor infiltration (CVI) interface welding. The insulating o-BN@SiC/epoxy (o-BN@SiC/EP) composites exhibited enhanced thermal conductivity benefited from the CVI-SiC-welded BN-BN interface. Further, multiscale simulation, combining first-principles calculation, Monte Carlo simulation, and finite-element simulation, was performed to quantitatively reveal the effect of the welded BN-BN interface on the heat transfer of o-BN@SiC/EP composites. Phonon transmission in solders and phonon-phonon coupling of filler-solder interfaces enhanced the interfacial heat transfer between adjacent h-BN microplatelets, and the interfacial thermal resistance of the dominant BN-BN interface was decreased to only 3.83 nK·m2/W from 400 nK·m2/W, plunging by over 99%. This highly weakened interfacial thermal resistance greatly improved the heat transfer along thermal pathways and resulted in a 26% thermal conductivity enhancement of o-BN@SiC/EP composites, compared with physically contacted oriented h-BN/EP composites, at 15 vol % h-BN. This systematic multiscale simulation broke through the barrier of revealing the heat transfer mechanism of polymer composites from the nanoscale to the macroscale, which provided rational cognition about the effect of the interfacial thermal resistance between fillers on the thermal conductivity of polymer composites.

Improved Thermal Anisotropy of Multi-Layer Tungsten Telluride on Silicon Substrate.

WTe2, a low-symmetry transition metal dichalcogenide, has broad prospects in functional device applications due to its excellent physical properties. When WTe2 flake is integrated into practical device structures, its anisotropic thermal transport could be affected greatly by the substrate, which matters a lot to the energy efficiency and functional performance of the device. To investigate the effect of SiO2/Si substrate, we carried out a comparative Raman thermometry study on a 50 nm-thick supported WTe2 flake (with κzigzag = 62.17 W·m-1·K-1 and κarmchair = 32.93 W·m-1·K-1), and a suspended WTe2 flake of similar thickness (with κzigzag = 4.45 W·m-1·K-1, κarmchair = 4.10 W·m-1·K-1). The results show that the thermal anisotropy ratio of supported WTe2 flake (κzigzag/κarmchair ≈ 1.89) is about 1.7 times that of suspended WTe2 flake (κzigzag/κarmchair ≈ 1.09). Based on the low symmetry nature of the WTe2 structure, it is speculated that the factors contributing to thermal conductivity (mechanical properties and anisotropic low-frequency phonons) may have affected the thermal conductivity of WTe2 flake in an uneven manner when supported on a substrate. Our findings could contribute to the 2D anisotropy physics and thermal transport study of functional devices based on WTe2 and other low-symmetry materials, which helps solve the heat dissipation problem and optimize thermal/thermoelectric performance for practical electronic devices.

Establishment and validation of a nomograph model for prediction of bronchopulmonary dysplasia in very low birth weight infants born earlier than 32 weeks / 中华围产医学杂志

Objective:To investigate the risk factors of bronchopulmonary dysplasia (BPD) in very low birth weight (VLBW) infants with gestational age ≤32 weeks within 28 days after birth and to establish and validate the nomogram model for BPD prediction.Methods:We retrospectively chose VLBW infants with gestational age ≤32 weeks who survived to postmenstrual age (PMA) 36 weeks and were admitted to the neonatal intensive care unit of Peking University Third Hospital from January 2016 to April 2020 as the training cohort. BPD was diagnosed in accordance with the 2018 criteria. The clinical data of these infants were collected, and the risk factors of BPD were analyzed by Chi-square test, Mann-Whitney U test, and multivariate logistic regression, and a nomogram model was established. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was used to assess the predictive performance. Decision curve analysis (DCA) was constructed for differentiation evaluation, and the calibration chart and Hosmer-Lemeshow goodness of fit test were used for the calibration evaluation. Bootstrap was used for internal validation. VLBW infants with gestational age ≤32 weeks survived to PMA 36 weeks and admitted to Hebei Chengde Maternal and Child Health Hospital from October 2017 to February 2022 were included as the validation cohort. ROC curve and calibration plot were conducted in the validation cohort for external validation. Results:Of the 467 premature infants included in the training cohort, 104 were in the BPD group; of the 101 patients in the external validation cohort, 16 were in the BPD group. Multivariate logistic regression analysis showed that low birth weight ( OR=0.03, 95% CI: 0.01-0.13), nosocomial pneumonia ( OR=2.40, 95% CI: 1.41-4.09), late-onset sepsis ( OR=2.18, 95% CI: 1.18-4.02), and prolonged duration of endotracheal intubation ( OR=1.61, 95% CI: 1.26-2.04) were risk factors for BPD in these groups of infants (all P<0.05). According to the multivariate logistic regression analysis results, a nomogram model for predicting BPD risk was established. The AUC of the training cohort was 0.827 (95% CI: 0.783-0.872), and the ideal cut-off value for predicted probability was 0.206, with a sensitivity of 0.788 (95% CI: 0.697-0.862) and specificity of 0.744 (95% CI: 0.696-0.788). The AUC of the validation cohort was 0.951 (95% CI:0.904-0.999). Taking the prediction probability of 0.206 as the high-risk threshold, the sensitivity and specificity corresponding to this value were 0.812 (95% CI: 0.537-0.950) and 0.882 (95% CI: 0.790-0.939). The Hosmer-Lemeshow goodness-of-fit test in the training and validation cohort showed a good fit ( P>0.05). DCA results showed a high net benefit of clinical intervention in very preterm infants when the threshold probability was 5%~80% for the training cohort. Conclusion:Low birth weight, nosocomial pneumonia, late-onset sepsis, and prolonged tracheal intubation duration are risk factors for BPD. The established nomogram model has a certain value in predicting the risk of BPD in VLBW less than 32 weeks.

Sagacious confucius' pillow elixir ameliorates Dgalactose induced cognitive injury in mice via estrogenic effects and synaptic plasticity.

Alzheimer's disease (AD) is a growing concern in modern society, and there is currently a lack of effective therapeutic drugs. Sagacious Confucius' Pillow Elixir (SCPE) has been studied for the treatment of neurodegenerative diseases such as AD. This study aimed to reveal the key components and mechanisms of SCPE's anti-AD effect by combining Ultra-high Performance Liquid Chromatography-electrostatic field Orbitrap combined high-resolution Mass Spectrometry (UPLC-LTQ/Orbitrap-MS) with a network pharmacology approach. And the mechanism was verified by in vivo experiments. Based on UPLC-LTQ/Orbitrap-MS technique identified 9 blood components from rat serum containing SCPE, corresponding to 113 anti-AD targets, and 15 of the 113 targets had high connectivity. KEGG pathway enrichment analysis showed that estrogen signaling pathway and synaptic signaling pathway were the most significantly enriched pathways in SCPE anti-AD, which has been proved by in vivo experiments. SCPE can exert estrogenic effects in the brain by increasing the amount of estrogen in the brain and the expression of ERα receptors. SCPE can enhance the synaptic structure plasticity by promoting the release of brain-derived neurotrophic factor (BDNF) secretion and improving actin polymerization and coordinates cofilin activity. In addition, SCPE also enhances synaptic functional plasticity by increasing the density of postsynaptic densified 95 (PSD95) proteins and the expression of functional receptor AMPA. SCPE is effective for treatment of AD and the mechanism is related to increasing estrogenic effects and improving synaptic plasticity. Our study revealed the synergistic effect of SCPE at the system level and showed that SCPE exhibits anti-AD effects in a multi-component, multi-target and multi-pathway manner. All these provide experimental support for the clinical application and drug development of SCPE in the prevention and treatment of AD.

Controlling anisotropic thermal properties of graphene aerogel by compressive strain.

Materials with adjustable wide-ranging thermal conductivity are desired to tackle the problem of thermal management for electronic devices operating in an extended range of temperature. In this study, graphene aerogels (GAs) are fabricated and transformed from thermal insulators to thermal conductors by high-temperature annealing. The highest through-plane and in-plane thermal conductivity of annealed GA reaches 3.3 and 96 W/m·K, respectively, under 95% compressive strain. Using the annealed GA as thermal interface material leads to superior performance than commercially available products that have higher through-plane thermal conductivity in dissipating heat for high-power electronic devices (e.g., LED lamp). Furthermore, due to excellent elasticity, the thermal resistance of annealed GAs can be reversibly tuned about six-fold by compressive strain. This paves a novel venue in designing thermal management system for devices, which not only need excellent heat dissipation but also good thermal insulation at various operating environments.

Free-standing graphene aerogel with improved through-plane thermal conductivity after being annealed at high temperature.

Both high through-plane thermal conductivity and low elastic modulus can reduce thermal interface resistance, which is important for thermal interface materials. The internal porous structure of graphene aerogel (GA) makes it to have a low elastic modulus, which results in its good compressibility. Also, the network structure of GA provides thermal conducting paths, which improve the through-plane thermal conductivity of GA. Annealing GA at 3000 °C helps to remove oxygen-containing functional groups and reduces defects. This greatly improves its crystallinity, which further leads to the improvement of its through-plane thermal conductivity and it has a low modulus of 1.37Mpa. The through-plane thermal conductivity of GA annealed at 3000 °C (GA-3000) was improved as the pressure increased and got to 2.93 W/ m K at a pressure of 1.13 MPa, which is 30 times higher than other graphene-based thermal interface materials (TIMs). These discoveries offer a novel approach for preparing excellent TIMs.

Impact of Ionic Liquids on Effectiveness of Tuning the Emissivity of Multilayer Graphene.

Multilayer graphene has been employed as a functional material for tuning the emissivity in mid- and long-infrared range, which shows great potential for various applications, such as radiative cooling and thermal camouflage. However, the stability of the multilayer graphene is not sufficient for practical applications yet. Even though it is reported that the integrity of the multilayer graphene is compromised by ion intercalation, the detailed mechanism is rather unclear. Here, a set of ionic liquids is deployed as sources of electronic charges for tuning the emissivity of multilayer graphene. It is found that the emissivity modulator using 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([EMIm]NTf2) as the ionic liquid provides a modulation depth of about 0.52 (i.e., about 21% larger than the best-reported value) while maintaining a reasonable device lifetime. The microscopic structures of the multilayer graphene in an operational and failure modulator are investigated by scanning electron microscopy, Raman spectroscopy, X-ray diffraction. The results indicate that the modulation depth of emissivity is negatively correlated with the initial voltage, which represents the reaction potential between the ionic liquid and graphene. Furthermore, not only the chemical reactivity but also the size of both anion and cation in the ionic liquids play important roles in maintaining stability of the modulator. Therefore, a set of criteria (e.g., low initial voltage and small size of anion and cation) is proposed to select proper ionic liquids for emissivity modulation. This not only sheds light on the underlying physics of the modulator but also promotes its practical applications.

Study on pathological mechanism and establishment of animal model of ICU acquired weakness / 医学研究生学报

ObjectiveThere are few animal experiments on ICU acquired weakness (ICU AW), and suitable animal models are the main constraints. The study was to explore the method of ICU AW animal model which satisfies the clinical requirements of ICU and suitable for large-scale animal trials.MethodsThirty six SD rats were randomly divided into Control group(0.9%NS at 2.5 ml/kg intraperitoneal injection once a day for consecutive 3 days), immobilization group(the left hindlimb was immobilizated for 7d, then the immobilization was removed to 14 d), sepsis group(lipopolysaccharide at 2.5 mg/kg intraperitoneal injection once a day for consecutive 3 days) and sepsis-immobilization group(the left hindlimb was immobilizated for 7d, then the immobilization was removed to 14 d and lipopolysaccharide at 2.5 mg/kg intraperitoneal injection once a day for consecutive 3 days).To determine whether the model was successful, the muscle strength of left hindlimb, gastrocnemius/body weight ratio and pathological changes of gastrocnemius were measured at 0 d( immediately after intervention), 3d, 7 d, 10 d, 14 d. To explore the possible pathological mechanism, creatinine/body weight ratio, albumin, lymphocyte, and gastrocnemius pathological scores were measured.Results7 days later, the scores of left hindlimb muscle strength and pathology in sepsis immobilization group were significantly higher than those in the sepsis group and the control group(P<0.05), contary body weight and gastrocnemius weight were lower than those in control group, immobilization group and sepsis group(P<0.05), and gastrocnmiu/body weight ratio(0.528±0.018) was significantly lower than those in control group(0.756±0.315) and sepsis group(0.813±0.040)(P<0.05). Creatinine / body weight in sepsis immobilization group(0.283±0.0268) was significantly higher than those of blank group (0.185±0.022), immobilization group (0.207±0.027) and sepsis group (0.246±0.043)(P<0.05). The lymphocyte count [(5.193±1.493) ×109/L] was significantly lower than that in the blank group[(7.005±0.702) ×109/L] and the immobilization group[(7.208±0.832) ×109/L)](P< 0.05). 14 days later, the scores of left hindlimb muscle strength, body and gastrocnemius weight in sepsis immobilization group were significantly lower than those in control group, immobilization group and sepsis group(P<0.05). Gastrocnmiu/body weight ratio in sepsis immobilization group(0.519± 1.493) was significantly lower than those in control group(0.798±0.015), immobilization group (0.570±0.022)and sepsis group(0.693±0.022)(P<0.05).ConclusionThe qualified animal model of ICU AW can be established by repeated intraperitoneal injection in low dose of lipopolysaccharide combined with limb immobilization. Immunosuppression and Hypercatabolism in ICU AW rats is an important reason that ICU AW can not to be mitigated. Thus, we supposed that it may be the mechanisms for the development of ICU AW,which needs further experimental verification.

Correction and removal of expression of concern: Controllable 2H-to-1T' phase transition in few-layer MoTe2.

Removal of expression of concern for 'Controllable 2H-to-1T' phase transition in few-layer MoTe2' by Yuan Tan et al., Nanoscale, 2018, 10, 19964-19971.

An approach to high-throughput growth of submillimeter transition metal dichalcogenide single crystals.

High-throughput growth of large size transition metal dichalcogenide (TMD) single crystals is an important challenge for their applications in the next generation electronic and optoelectronic integration devices. Here we report the high-throughput growth of submillimeter monolayer TMD single crystals by two-stage space confined chemical vapor deposition, where the nucleation density of TMD crystals is significantly decreased for the growth of large size monolayer crystals by the space confinement effect. Moreover, high-throughput growth of submillimeter TMD crystals is also achieved by stacking the substrates along the perpendicular direction to the flow of the reaction gases. The mobilities of the TMD materials produced in this way are up to 1.2, 17.0 and 25.0 cm2 (V s)-1 for monolayer WS2, WSe2 and MoS2 single crystals, respectively. The results demonstrate that two-stage space confined growth is a highly promising method for high-throughput fabrication of high-quality submillimeter monolayer TMD single crystals, which will pave a new pathway to large-scale production of TMD-based electronic and optoelectronic devices.

Controllable 2H-to-1T' phase transition in few-layer MoTe2.

Most two-dimensional (2D) transition metal dichalcogenides (TMDs) exhibit more than one structural phase, leading to a number of remarkable physics and potential device applications beyond graphene. Here, we demonstrated a feasible route to trigger 2H-to-1T' phase transition in few-layer molybdenum ditelluride (MoTe2) by laser irradiation. The effects of laser power and irradiation duration were systematically studied in this study, revealing the accumulated heating effect as the main driving force for such a phase transition. By carefully adjusting laser power and irradiation time, we could control the structural phases of MoTe2 as 2H, 2H + 1T', and 1T'. After thermal annealing at a rather low temperature, the laser-irradiated MoTe2 showed a completely suppressed 2H component and a more stabilized 1T' phase, demonstrating that the microscopic origin of the irreversible 2H-to-1T' phase transition is the formation of Te vacancies in MoTe2 due to laser local instantaneous heating. Our findings together with the unique properties of MoTe2 pave the way for high-performance nanoelectronics and optoelectronics based on 2D TMDs and their heterostructures.

Phase-Controlled Growth of One-Dimensional Mo6Te6 Nanowires and Two-Dimensional MoTe2 Ultrathin Films Heterostructures.

Controllable synthesizing of one-dimensional-two-dimensional (1D-2D) heterostructures and tuning their atomic and electronic structures is nowadays of particular interest due to the extraordinary properties and potential applications. Here, we demonstrate the temperature-induced phase-controlled growth of 1D Mo6Te6-2D MoTe2 heterostructures via molecular beam epitaxy. In situ scanning tunneling microscopy study shows 2D ultrathin films are synthesized at low temperature range, while 1D nanowires gradually arise and dominate as temperature increasing. X-ray photoelectron spectroscopy confirms the good stoichiometry and scanning tunneling spectroscopy reveals the semimetallic property of grown Mo6Te6 nanowires. Through in situ annealing, a phase transition from 2D MoTe2 to 1D Mo6Te6 is induced, thus forming a semimetal-semiconductor junction in atomic level. An upward band bending of 2H-MoTe2 is caused by lateral hole injection from Mo6Te6. The work suggests a new route to synthesize 1D semimetallic transition metal chalcogenide nanowires, which could serve as ultrasmall conducting building blocks and enable band engineering in future 1D-2D heterostructure devices.

The clinical relevance of MBL2 gene polymorphism and sepsis

Objective:To detect the clinical relevance of mannose-binding lectin 2 (MBL2) gene polymorphism and sepsis in Chinese lived in Hainan island.Methods:Blood samples from 57 patients with sepsis and 69 patients without sepsis were collected in the ICU of several large hospitals in Hainan province. Genomic DNA was extracted from whole blood and then PCR purification product was sequenced and typed by 3730 sequencing analyzer. The concentration of MBL2 in serum was detected by ELISA.Results:We found that genotype and allele distributions in two groups were in accordance with the Hardy-Weinberg Equilibrium. The frequency of GA genotype was significantly higher than that in non-sepsis group (P=0.013). A allele frequency in sepsis group was also much higher than that in non-sepsis group (P=0.028). Logister regression analysis showed that the patients who carried A allele were more prone to get sepsis than G allele carrier (P=0.014, 0R=2.550, 95%CI=1.207-5.386). The MBL2 level in serum of sepsis patients with genotype GG and GA was significantly lower than that in non-sepsis group (P<0.05). In sepsis group, the MBL2 serum level of patients with genotype GA was obviously lower than that in patients with genotype GG (P<0.05).Conclusions:The variation of rs1800450 G→A increased the incidence of sepsis and decreased the level of MBL2 in serum.

The clinical relevance of MBL2 gene polymorphism and sepsis

Objective: To detect the clinical relevance of mannose-binding lectin 2 (MBL2) gene polymorphism and sepsis in Chinese lived in Hainan island. Methods: Blood samples from 57 patients with sepsis and 69 patients without sepsis were collected in the ICU of several large hospitals in Hainan province. Genomic DNA was extracted from whole blood and then PCR purification product was sequenced and typed by 3730 sequencing analyzer. The concentration of MBL2 in serum was detected by ELISA. Results: We found that genotype and allele distributions in two groups were in accordance with the Hardy-Weinberg Equilibrium. The frequency of GA genotype was significantly higher than that in non-sepsis group (P=0.013). A allele frequency in sepsis group was also much higher than that in non-sepsis group (P=0.028). Logister regression analysis showed that the patients who carried A allele were more prone to get sepsis than G allele carrier (P=0.014, 0R=2.550, 95%CI=1.207-5.386). The MBL2 level in serum of sepsis patients with genotype GG and GA was significantly lower than that in non-sepsis group (P<0.05). In sepsis group, the MBL2 serum level of patients with genotype GA was obviously lower than that in patients with genotype GG (P<0.05). Conclusions: The variation of rs1800450 G→A increased the incidence of sepsis and decreased the level of MBL2 in serum.