The dynamic surface evolution of halide perovskites induced by external energy stimulation

Tracking the dynamic surface evolution of metal halide perovskite is crucial for understanding the corresponding fundamental principles of photoelectric properties and intrinsic instability. However, due to the volatility elements and soft lattice nature of perovskites, several important dynamic behaviors remain unclear. Here, an ultra-high vacuum (UHV) interconnection system integrated by surface-sensitive probing techniques has been developed to investigate the freshly cleaved surface of CH3NH3PbBr3  in situ under given energy stimulation. On this basis, the detailed three-step chemical decomposition pathway of perovskites has been clarified. Meanwhile, the evolution of crystal structure from cubic phase to tetragonal phase on the perovskite surface has been revealed under energy stimulation. Accompanied by chemical composition and crystal structure evolution, electronic structure changes including energy level position, hole effective mass, and Rashba splitting have also been accurately determined. These findings provide a clear perspective on the physical origin of optoelectronic properties and the decomposition mechanism of perovskites.

Deciphering Vacancy Defect Evolution of 2D MoS2 for Reliable Transistors

Two-dimensional (2D) MoS2 is an excellent candidate channel material for next-generation integrated circuit (IC) transistors. However, the reliability of MoS2 is of great concern due to the serious threat of vacancy defects, such as sulfur vacancies (VS). Evaluating the impact of vacancy defects on the service reliability of MoS2 transistors is crucial, but it has always been limited by the difficulty in systematically tracking and analyzing the changes and effects of vacancy defects in the service environment. Here, a simulated initiator is established for deciphering the evolution of vacancy defects in MoS2 and their influence on the reliability of transistors. The results indicate that VS below 1.3% are isolated by slow enrichment during initiation. Over 1.3% of VS tend to enrich in pairs and over 3.5% of the enriched VS easily evolve into nanopores. The enriched VS with electron doping in the channel cause the threshold voltage (Vth) negative drift approaching 6 V, while the expanded nanopores initiate the Vth roll-off and punch-through of transistors. Finally, sulfur steam deposition has been proposed to constrain VS enrichment, and reliable MoS2 transistors are constructed. Our research provides a new method for deciphering and identifying the impact of defects.

Conformal Human-Machine Integration Using Highly Bending-Insensitive, Unpixelated, and Waterproof Epidermal Electronics Toward Metaverse

Efficient and flexible interactions require precisely converting human intentions into computer-recognizable signals, which is critical to the breakthrough development of metaverse. Interactive electronics face common dilemmas, which realize high-precision and stable touch detection but are rigid, bulky, and thick or achieve high flexibility to wear but lose precision. Here, we construct highly bending-insensitive, unpixelated, and waterproof epidermal interfaces (BUW epidermal interfaces) and demonstrate their interactive applications of conformal human-machine integration. The BUW epidermal interface based on the addressable electrical contact structure exhibits high-precision and stable touch detection, high flexibility, rapid response time, excellent stability, and versatile "cut-and-paste" character. Regardless of whether being flat or bent, the BUW epidermal interface can be conformally attached to the human skin for real-time, comfortable, and unrestrained interactions. This research provides promising insight into the functional composite and structural design strategies for developing epidermal electronics, which offers a new technology route and may further broaden human-machine interactions toward metaverse.

Boosting Charge Utilization in Self-Powered Photodetector for Real-Time High-Throughput Ultraviolet Communication

Ultraviolet (UV) communication is a cutting-edge technology in communication battlefields, and self-powered photodetectors as their optical receivers hold great potential. However, suboptimal charge utilization has largely limited the further performance enhancement of self-powered photodetectors for high-throughput communication application. Herein, a self-powered Ti3 C2 Tx -hybrid poly(3,4 ethylenedioxythiophene):poly-styrene sulfonate (PEDOT:PSS)/ZnO (TPZ) photodetector is designed, which aims to boost charge utilization for desirable applications. The device takes advantage of photothermal effect to intensify pyro-photoelectric effect as well as the increased conductivity of the PEDOT:PSS, which significantly facilitated charge separation, accelerated charge transport, and suppressed interface charge recombination. Consequently, the self-powered TPZ photodetector exhibits superior comprehensive performance with high responsivity of 12.3 mA W-1 and fast response time of 62.2 µs, together with outstanding reversible and stable cyclic operation. Furthermore, the TPZ photodetector has been successfully applied in an integrated UV communication system as the self-powered optical receiver capable of real-time high-throughput information transmission with ASCII code under 9600 baud rate. This work provides the design insight of highly performing self-powered photodetectors to achieve high-efficiency optical communication in the future.

Morphotropic Phase Boundary in Polarized Organic Piezoelectric Materials

Designing the morphotropic phase boundary (MPB) has been the most sought-after approach to achieve high piezoelectric performance of piezoelectric materials. However, MPB has not yet been found in the polarized organic piezoelectric materials. Here, we discover MPB with biphasic competition of β and 3/1-helical phases in the polarized piezoelectric polymer alloys (PVTC-PVT) and demonstrate a mechanism to induce MPB using the compositionally tailored intermolecular interaction. Consequently, PVTC-PVT exhibits a giant quasistatic piezoelectric coefficient of >32  pC/N while maintaining a low Young's modulus of 182 MPa, with a record-high figure of merit of piezoelectricity modulus of about 176  pC/(N·GPa) among all piezoelectric materials.

Roles of Low-Dimensional Nanomaterials in Pursuing Human-Machine-Thing Natural Interaction

A wide variety of low-dimensional nanomaterials with excellent properties can meet almost all the requirements of functional materials for information sensing, processing, and feedback devices. Low-dimensional nanomaterials are becoming the star of hope on the road to pursuing human-machine-thing natural interactions, benefiting from the breakthroughs in precise preparation, performance regulation, structural design, and device construction in recent years. This review summarizes several types of low-dimensional nanomaterials commonly used in human-machine-thing natural interactions and outlines the differences in properties and application areas of different materials. According to the sequence of information flow in the human-machine-thing interaction process, the representative research progress of low-dimensional nanomaterials-based information sensing, processing, and feedback devices is reviewed and the key roles played by low-dimensional nanomaterials are discussed. Finally, the development trends and existing challenges of low-dimensional nanomaterials in the field of human-machine-thing natural interaction technology are discussed.

Identifying and Interpreting Geometric Configuration-Dependent Activity of Spinel Catalysts for Water Reduction

The catalytic activity of transition metal-based catalysts is overwhelmingly dependent on the geometric configuration. Identification and interpretation of different geometric configurations' contributions to catalytic activity plays a pivotal role in catalytic performance elevation. Spinel structured AB₂X₄, consisting of tetrahedral (A²⁺-X)_Td and octahedral (B³⁺-X)_Oh geometric configurations, is a prototypical category of multi-geometric-configuration featured catalysts. However, it is still under debate about the predominant geometric configuration responsible for spinel catalyst activity, and the mechanistic origin of specific activity discrepancy among varied geometric configurations also remains ambiguous. Herein, Co_Td²⁺ and Co_Oh³⁺ in Co₃O₄ are replaced by catalytically inert Zn²⁺ and Al³⁺ to yield ZnCo₂O₄ and CoAl₂O₄, respectively, thus ensuring the manipulable exposure of monotypic active configurations. By means of pulse voltammetry and in situ extended X-ray absorption fine structure, (Co³⁺-O)_Oh is identified to be dominant for alkaline HER. In-depth theoretical investigation in combination with X-ray absorption spectroscopy further interprets the synergistic effect between Co and O sites in (Co³⁺-O)_Oh configuration on water reduction kinetics upon both water dissociation and hydrogen desorption steps. Furthermore, specific facet dependence of catalytic activity is also deciphered based on precise facet exposure identification and serial theoretical analysis. This work unambiguously figures out the subtle geometric configuration dependence of spinel catalyst activity for water reduction and highlights the synergistic relationship among different components confined in geometric configuration, thereby shedding new light on the rational design of advanced catalysts from the atomic level of geometric configuration optimization.

Synthesis of Large-Area MXenes with High Yields through Power-Focused Delamination Utilizing Vortex Kinetic Energy

Evaluating the delamination process in the synthesis of MXenes (2D transition metal carbides and nitrides) is critical for their development and applications. However, the preparation of large defect-free MXene flakes with high yields is challenging. Here, a power-focused delamination (PFD) strategy is demonstrated that can enhance both the delamination efficiency and yield of large Ti₃ C₂ T_x MXene nanosheets through repetitive precipitation and vortex shaking processes. Following this protocol, a colloidal concentration of 20.4 mg mL^-1 of the Ti₃ C₂ T_x MXene can be achieved after five PFD cycles, and the yield of the basal-plane-defect-free Ti₃ C₂ T_x nanosheets reaches 61.2%, which is 6.4-fold higher than that obtained using the sonication-exfoliation method. Both nanometer-thin devices and self-supporting films exhibit excellent electrical conductivities (≈25 000 and 8260 S cm^-1 for a 1.8 nm thick monolayer and 11 µm thick film, respectively). Hydrodynamic simulations reveal that the PFD method can efficiently concentrate the shear stress on the surface of the unexfoliated material, leading to the exfoliation of the nanosheets. The PFD-synthesized large MXene nanosheets exhibit superior electrical conductivities and electromagnetic shielding (shielding effectiveness per unit volume: 35 419 dB cm² g^-1 ). Therefore, the PFD strategy provides an efficient route for the preparation of high-performance single-layer MXene nanosheets with large areas and high yields.

All-van-der-Waals Barrier-Free Contacts for High-Mobility Transistors

Ultrathin 2D semiconductor devices are considered to have beyond-silicon potential but are severely troubled by the high Schottky barriers of the metal-semiconductor contacts, especially for p-type semiconductors. Due to the severe Fermi-level pinning effect and the lack of conventional semimetals with high work functions, their Schottky hole barriers are hardly removed. Here, an all-van-der-Waals barrier-free hole contact between p-type tellurene semiconductor and layered 1T'-WS₂ semimetal is reported, which achieves a zero Schottky barrier height of 3 ± 9 meV and a high field-effect mobility of ≈1304 cm² V^-1 s^-1 . The formation of such contacts can be attributed to the higher work function of ≈4.95 eV of the 1T'-WS₂ semimetal, which is in sharp contrast with low work function (4.1-4.7 eV) of conventional semimetals. The study defines an available strategy for eliminating the Schottky barrier of metal-semiconductor contacts, facilitating 2D-semiconductor-based electronics and optoelectronics to extend Moore's law.

[Evaluation of severity and prognosis of acute pancreatitis by CT severity index and modified CT severity index]

Objectives: To explore the role of computed tomography (CT) severity index (CTSI) and modified CT severity index (MCTSI) in assessing the severity of acute pancreatitis (AP) under the revised Atlanta classification (RAC) and predicting the clinical prognosis. Methods: Based on the prospectively entered AP database, the clinical data of consecutive adult AP inpatients admitted to the Department of Gastroenterology of the First Affiliated Hospital of Nanchang University from January 2012 to December 2020 were retrospectively screened. The imaging data were independently evaluated by two radiologists and entered to the database to calculate the CTSI and MCTSI scores. Their relationship with the difference of RAC severity grade and clinical prognosis was analyzed. Compared with Acute Physiology and Chronic Health Assessment Ⅱ (APACHE Ⅱ) score, the receiver operating characteristic curve was used to evaluate the predictive value of CTSI and MCTSI scores for persistent organ failure and infectious pancreatic necrosis (IPN). Results: A total of 2 612 patients with AP, aged (50±15) years, were included in the study, including 1 547 males (59.2%) and 1 065 females (40.8%). According to RAC standard, AP was divided into 699 cases (26.8%) of mild pancreatitis (MAP), 1 098 cases (42.0%) of moderately severe pancreatitis (MSAP), and 815 cases (31.2%) of severe pancreatitis (SAP). MCTSI judged AP severity similarly to RAC, with 668 cases of MAP (25.6%), 1 207 cases of MSAP (46.2%) and 737 cases of SAP (28.2%), while CTSI judged SAP patients less(400 cases, 15.3%). The severity of AP determined by CTSI and MCTSI scores was significantly correlated with clinical prognosis (r=0.06-0.43, all P<0.05). Compared with APACHE Ⅱ score, CTSI had the highest area under the curve (AUC) for predicting IPN (AUC=0.85, 95%CI: 0.83-0.87), followed by MCTSI (AUC=0.82, 95%CI: 0.80-0.85). APACHE Ⅱ was more accurate in predicting persistent organ failure than CTSI and MCTSI scores,with AUC of 0.73 (95%CI: 0.71-0.75), 0.72 (95%CI: 0.70-0.74) and 0.72 (95%CI: 0.70-0.74), respectively. Conclusions: AP severity judged by MCTSI is consistent with RAC, and SAP patients judged by CTSI are less than RAC. CTSI and MCTSI are significantly correlated with clinical prognosis. CTSI and MCTSI have higher accuracy in predicting IPN, but lower accuracy in predicting persistent organ failure than APACHE Ⅱ.

[Update on the medical management of parathyroid carcinoma]

Parathyroid carcinoma is a rare endocrine malignancy with an increasing rate of incidence. Most parathyroid carcinoma patients will develop local recurrence or metastases leading to poor prognosis. Medical management is the mainstay of treatment for patients with unresectable parathyroid carcinoma. However, the therapeutic outcome of medical management remains unsatisfactory restricted by limited options and efficacy. With the deepening of research, several novel drugs have been reported to be applied in the treatment of parathyroid carcinoma. Calcimimetics and receptor activator for nuclear factor-κB ligand inhibitors aiming to control hypercalcemia have been applied in the endocrine therapy of parathyroid carcinoma. Besides, preliminary studies have shown the therapeutic effects of targeted therapy and immunotherapy on parathyroid carcinoma. These new drugs have shed light on this clinical dilemma; however, their clinical efficacy remains to be determined. In this article, the recent progress in the medical management of parathyroid carcinoma is updated.

Interpretation of Rubidium-Based Perovskite Recipes toward Electronic Passivation and Ion-Diffusion Mitigation

Rubidium cation (Rb⁺ ) addition is witnessed to play a pivotal role in boosting the comprehensive performance of organic-inorganic hybrid perovskite solar cells. However, the origin of such success derived from irreplaceable superiorities brought by Rb⁺ remains ambiguous. Herein, grain-boundary-including atomic models are adopted for the accurate theoretical analysis of practical Rb⁺ distribution in perovskite structures. The spatial distribution, covering both the grain interiors and boundaries, is thoroughly identified by virtue of synchrotron-based grazing-incidence X-ray diffraction. On this basis, the prominent elevation of the halogen vacancy formation energy, improved charge-carrier dynamics, and the electronic passivation mechanism in the grain interior are expounded. As evidenced by the increased energy barrier and suppressed microcurrent, the critical role of Rb⁺ addition in blocking the diffusion pathway along grain boundaries, inhibiting halide phase segregation, and eventually enhancing intrinsic stability is elucidated. Hence, the linkage avalanche effect of occupied location dominated by subtle changes in Rb⁺ concentration on electronic defects, ion migration, and phase stability is completely investigated in detail, shedding a new light on the advancement of high-efficiency cascade-incorporating strategies and perovskite compositional engineering.

A van der Waals Ferroelectric Tunnel Junction for Ultrahigh-Temperature Operation Memory

Facing the constant scaling down and thus increasingly severe self-heating effect, developing ultrathin and heat-insensitive ferroelectric devices is essential for future electronics. However, conventional ultrathin ferroelectrics and most 2D ferroelectric materials (2DFMs) are not suitable for high-temperature operation due to their low Curie temperature. Here, by using few-layer α-In₂ Se₃ , a special 2DFM with high Curie temperature, van der Waals (vdW) ferroelectric tunnel junction (FTJ) memories that deliver outstanding and reliable performance at both room and high temperatures are constructed. The vdW FTJs offer a large on/off ratio of 10⁴ at room temperature and still reveal excellent on/off ratio at an ultrahigh temperature of 470 K, which will fail down other 2DFMs. Moreover, long retention and reliable cyclic endurance at high temperature are achieved, showing robust thermal stability of the vdW FTJ memory. The observations of this work demonstrate an exciting promise of α-In₂ Se₃ for reliable service in high temperature either from self-heating or harsh environments.

[Relationship between nutritional factors and clinical outcome in children with tuberculous meningitis]

Objective: To investigate the relationship between nutritional risk status and clinical outcome in children with tuberculous meningitis (TBM). Methods: The clinical data (basic information, clinical symptoms and laboratory test results) of 112 patients with TBM, who were admitted to Department of Pediatric Infectious Diseases of West China Second Hospital of Sichuan University,from January 2013 to December 2020 were retrospectively analyzed. The patients were divided into the nutritional risk group and the non-nutritional risk group according to the assessment of the nutritional risk by the STRONGkids Scale. The variables of basic information, clinical symptoms and laboratory test measurements etc. were compared between the two groups by using Student t test, Rank sum test or Chi-square test. Multivariate Logistic regression analysis were used to analyze nutritional risk factors. Results: Among 112 patient with TBM, 55 were males and 57 females. There were 62 cases in the nutritional risk group and 50 cases in the non-nutritional risk group. The proportion of cases with nutritional risk was 55.4% (62/112). Patients in the nutritional risk who lived in rural areas, had symptoms of brain nerve damage, convulsions, emaciation and anorexia, with a diagnosis time of ≥21 days, and the level of cerebrospinal fluid (CSF) protein were all higher than those in the non-nutritional risk group ((50 cases (80.6%) vs. 32 cases (64.0%), 20 cases (32.3%) vs.8 cases (16.0%), 33 cases (53.2%) vs. 15 cases (30.0%), 30 cases (48.4%) vs. 2 cases (4.0%), 59 cases (95.2%) vs. 1 case (2.0%),41 cases (66.1%) vs.18 cases (36.0%), 1 406 (1 079, 2 068) vs. 929 (683, 1 208) mg/L, χ²=3.91, 3.90, 6.10, 26.72, 98.58, 10.08, Z=4.35, all P<0.05). The levels of serum albumin,hemoglobin,lymphocyte count, white blood cell count, and CSF glucose were significantly lower in patients with nutritional risk ((36±5) vs. (41±4) g/L, (110±17) vs. (122±14) g/L, 1.4 (1.0, 2.0)vs. 2.3 (1.6, 3.8)×10⁹/L, 7.8 (6.3, 10.0)×10⁹ vs. 10.0 (8.3, 12.8)×10⁹/L, 1.0 (0.8, 1.6) vs. 2.1 (1.3, 2.5) mmol/L, t=-6.15, -4.22, Z=-4.86, -3.92, -4.16, all P<0.05).Increased levels of serum albumin (OR=0.812, 95%CI:0.705-0.935, P=0.004) and lymphocyte count (OR=0.609, 95%CI:0.383-0.970, P=0.037) may reduce the nutritional risk of children with TBM; while convulsions (OR=3.853, 95%CI:1.116-13.308, P=0.033) and increased level of CSF protein (OR=1.001,95%CI:1.000-1.002, P=0.015) may increase the nutritional risk of children with TBM. Similarly, the rate of complications and drug-induced liver injury was higher in the nutritional risk group (47 cases (75.8%) vs. 15 cases(30.0%), 31 cases (50.0%) vs.8 cases (16.0%), χ²=23.50, 14.10, all P<0.05). Moreover, the length of hospital stay was also longer in the nutritional risk group ((27±13) vs. (18±7) d, t=4.38, P<0.05). Conclusions: Children with TBM have a high incidence of nutritional risk. Convulsive, the level of serum albumin, the level of lymphocyte count and CSF protein may affect the nutritional risk of children with TBM. The nutritional risk group has a high incidence of complications and heavy economic burden.It is necessary to carry out nutritional screening and nutritional support for children with TBM as early as possible.

MDM2 is involved in the regulation of p53 expression in the immune response of oyster Crassostrea hongkongensis

MDM2 (mouse double-minute) and p53 form a negative feedback loop and play a prominent role in preventing the induction of uncontrolled apoptosis. To better understand their potential roles in oyster Crassostrea hongkongensis, MDM2 and p53 homologs were first isolated and cloned in C. hongkongensis (named ChMDM2 and Chp53), and their mRNA expression patterns in tissues and developmental stages were analyzed. Multiple sequence alignment analysis and phylogenetic analysis of ChMDM2 and Chp53 displayed a high degree of homology and conservation. In addition, exposure to Vibrio coralliilyticus resulted in DNA damage and apoptosis in the hemocytes of C. hongkongensis, and found that the mRNA expression level of ChMDM2 was decreased, while the relative expression of Chp53 was significantly increased in the hemocytes and gills. Furthermore, fluorescence from ChMDM2-EGFP and Chp53-Red were found to be distributed in the nucleus of HEK293T cells. Besides, dual-luciferase reporter assays showed that ChMDM2 antagonized with Chp53 and participates in p53 signaling pathway. In addition, the interaction between ChMDM2 and Chp53 was confirmed strongly by Co-immunoprecipitation assays. Furthermore, the results of RNAi showed that ChMDM2 and Chp53 participated in apoptosis which induced infection of V. coralliilyticus. Taken together, our results characterized the features of ChMDM2 and Chp53, which played a critical role in apoptosis of C. hongkongensis.

396 Rotator Cuff Assessment Following Traumatic Anterior Shoulder Dislocation

Aim

Glenohumeral joint dislocation is the most common traumatic joint dislocation with a high recurrence rate correlating with age at first dislocation. There is an associated increased incidence in concurrent rotator cuff tears with increasing age affecting 40% aged 40–60. Patient care was assessed against BESS/BOA standard: These patients should have rotator cuff assessment and those aged 40–60 should undergo routine MRI/Ultrasound imaging.

Method

All patients admitted to the emergency departments of the 3 Lanarkshire hospitals undergoing first time traumatic anterior dislocation of the shoulder in February 2021 were included. This was the third cycle of this audit. Previous interventions were presentation at a CPD meeting after cycle one and an NHS Lanarkshire regional meeting after cycle two.

Results

Cycle one (2018)-14 patients. 3/14 underwent rotator cuff assessment. 5/14 aged 40–60. 1/5 underwent rotator cuff imaging.

Cycle two (2020)-11 patients. 0/9 underwent rotator cuff assessment (Two excluded as managed operatively). 4/11 aged 40–60. 0/4 underwent rotator cuff imaging.

Cycle three (2021)-13 patients. 3/11 underwent rotator cuff assessment (Two excluded as managed operatively). 3/13 aged 40–60. 0/3 underwent rotator cuff imaging.

Conclusions

Although a slight improvement has been made over the 3 cycles with rotator cuff assessment the BOA standard is not being met. There has been no improvement in the additional imaging required in traumatic anterior shoulder dislocations in those aged 40–60 over the 3 cycles. These patients may develop pain, reduced function, and rotator cuff arthropathy. There is now an aim to introduce a pathway for these patients across the health board.

Architecture Design and Interface Engineering of Self-assembly VS4/rGO Heterostructures for Ultrathin Absorbent

The employment of microwave absorbents is highly desirable to address the increasing threats of electromagnetic pollution. Importantly, developing ultrathin absorbent is acknowledged as a linchpin in the design of lightweight and flexible electronic devices, but there are remaining unprecedented challenges. Herein, the self-assembly VS4/rGO heterostructure is constructed to be engineered as ultrathin microwave absorbent through the strategies of architecture design and interface engineering. The microarchitecture and heterointerface of VS4/rGO heterostructure can be regulated by the generation of VS4 nanorods anchored on rGO, which can effectively modulate the impedance matching and attenuation constant. The maximum reflection loss of 2VS4/rGO40 heterostructure can reach - 43.5 dB at 14 GHz with the impedance matching and attenuation constant approaching 0.98 and 187, respectively. The effective absorption bandwidth of 4.8 GHz can be achieved with an ultrathin thickness of 1.4 mm. The far-reaching comprehension of the heterointerface on microwave absorption performance is explicitly unveiled by experimental results and theoretical calculations. Microarchitecture and heterointerface synergistically inspire multi-dimensional advantages to enhance dipole polarization, interfacial polarization, and multiple reflections and scatterings of microwaves. Overall, the strategies of architecture design and interface engineering pave the way for achieving ultrathin and enhanced microwave absorption materials.

Omnibearing Interpretation of External Ions Passivated Ion Migration in Mixed Halide Perovskites

Fundamental understanding of ion migration inside perovskites is of vital importance for commercial advancements of photovoltaics. However, the mechanism for external ions incorporation and its effect on ion migration remains elusive. Herein, taking K⁺ and Cs⁺ co-incorporated mixed halide perovskites as a model, the impact of external ions on ion migration behavior has been interpreted via multiple dimensional characterization aspects. The space-effect on phase segregation inhibition has been revealed by the photoluminescence evolution and in situ dynamic cathodoluminescence behaviors. The plane-effect on current suppression along grain boundary has been evidenced via visualized surface current mapping, local current hysteresis, and time-resolved current decay. And the point-effect on activation energy incremental for individual ions has been also probed by cryogenic electronic quantification. All these results sufficiently demonstrate the passivated ion migration results in the eventually improved phase stability of perovskite, of which the origin lies in various ion migration energy barriers.

Gold Catalyst Anchored to Pre-Reduced Co3O4 Nanorods for the Hydrodeoxygenation of Vanillin Using Alcohols as Hydrogen Donors

The preparation of highly dispersed metal catalysts with strong electronic metal-support interactions (EMSIs) is of great significance. In this study, oxygen vacancies (OVs) were generated on the surfaces of Co₃O₄ nanorods (NRs) through NaBH₄ treatment, and then the generated surface OVs were used to anchor gold clusters. The resulting catalyst was used for the hydrodeoxygenation (HDO) of vanillin based on transfer hydrogenation with alcohol donors. The conversion of vanillin and the selectivity to 2-methoxy-4-methylphenol (MMP) both reached 99% under the optimized reaction conditions, and these values were significantly higher than those obtained for the gold catalyst supported on the untreated Co₃O₄ NRs. The obtained results were verified by theoretical calculations and experimental data and confirmed the existence of strong EMSIs between the OV-enriched Co₃O₄ NRs (Co₃O₄ NRs-OVs) and the gold clusters, which allows electron transfer from the Co₃O₄ NRs to gold. Increasing the number of electrons on the gold surface can promote the catalytic hydrogen transfer of alcohol, in addition to selectively adsorbing the C═O group in vanillin to improve the selectivity toward MMP. This strategy based on the OV-anchoring of metals onto the surface of a support can be extended to other metals, thereby providing a promising method for the design of advanced and highly efficient metal catalysts.

Repurposing Ivermectin to augment chemotherapy's efficacy in osteosarcoma

BACKGROUND

Osteosarcoma is the most frequent malignant bone malignancy and the current treatments are ineffective. Ivermectin, an anti-protozoal drug, has been shown to have anti-cancer activity. This work investigated the potential of repurposing ivermectin to augment chemotherapy's efficacy in osteosarcoma.

METHODS

Proliferation, migration and apoptosis assays were performed in ivermectin-treated osteosarcoma cells. Combination studies were performed. Osteosarcoma xenograft mouse model was established to investigate the in vivo efficacy of ivermectin. Intracellular reactive oxygen species (ROS) and mitochondrial superoxide, membrane potential, ATP, 8-OHdG level, protein carbonylation and lipid peroxidation were determined after ivermectin treatment.

RESULTS

Ivermectin was effective and acted synergistically with doxorubicin in osteosarcoma cells regardless of cellular origin and genetic profiling. This was achieved through suppressing inhibiting growth and migration, and inducing caspase-dependent apoptosis. Ivermectin also significantly inhibited osteosarcoma growth in vivo and its combination with doxorubicin resulted in much greater efficacy than doxorubicin alone. Importantly, the effective dose of ivermectin was clinically feasible and did not cause significant toxicity in mice. Mechanistical analysis showed that ivermectin induced oxidative stress and damage, and mitochondrial dysfunction.

CONCLUSIONS

Our findings indicate that ivermectin has utility in treating patients with osteosarcoma, especially those resistant to chemotherapy.

Tough and Degradable Self-Healing Elastomer from Synergistic Soft-Hard Segments Design for Biomechano-Robust Artificial Skin

Increasing biomechanical applications of skin-inspired devices raise higher requirements for the skin-bionic robustness and environmental compatibility of elastomers. Here, a tough and degradable self-healing elastomer (TDSE) is developed by a synergistic soft-hard segments design. The polyester/polyether copolymer is introduced in soft segments to endow TDSE with flexibility and degradability. The two isomeric diamines are regulated in hard segments for elevating the toughness and fracture energy to 82.38 MJ/m³ and 43299 J/m² and autonomous self-healing ability with 93% efficiency in 7 h for the TDSE. Employing TDSE and ionic liquid, a biomechano-robust artificial skin (BA-skin) is constructed with a stretch-insensitive mechanosensation capability during 50% cyclic stretching. The BA-skin has high biomechano-robustness to bear tear damage and good environmental compatibility with total decomposability in a lipase solution. This work provides a molecular design guideline for high-performance skin-bionic elastomers for applications in skin-inspired devices.

A prospective study on vulvovaginal candidiasis: multicentre molecular epidemiology of pathogenic yeasts in China

BACKGROUND

Vulvovaginal candidiasis (VVC) is frequent in women of reproductive age, but very limited data are available on the epidemiology in cases of VVC in China.

OBJECTIVES

The current study has been conducted to reveal the prevalence, species distribution of yeast causing VVC and molecular genetics of Candida albicans in China.

METHODS

Vaginal swabs were collected from 543 VVC outpatients recruited in 12 hospitals in China between September 2017 and March 2018. They were preliminarily incubated on Sabouraud dextrose agar and then positive subjects of which were then transmitted to our institute for further identification. CHROMagar™ was used to isolate Candida species, and all isolates were finally identified by DNA sequencing. Multilocus sequence typing (MLST) was used to analyse phylogenetic relationships of the various C. albicans isolates.

RESULTS

Eleven different yeast species were identified in 543 isolates, among which C. albicans (84.7%) was the most frequent, followed by C. glabrata (8.7%). We obtained 117 unique diploid sequence types from 451 clinical C. albicans isolates and 92 isolates (20.4%) belonged to a New Clade. All the strains appearing in the New Clade were from northern China and they were isolated from non-recurrent VVC.

CONCLUSIONS

Our findings suggest that C. albicans are still the main cause of VVC in China and the majority of C. albicans isolates belongs to Clade 1 with DST 79 and DST 45 being two most common. Moreover, the New Clade revealed in our study seems to be specific to northern China.

Single-Atom Engineering to Ignite 2D Transition Metal Dichalcogenide Based Catalysis: Fundamentals, Progress, and Beyond

Single-atom catalysis has been recognized as a pivotal milestone in the development history of heterogeneous catalysis by virtue of its superior catalytic performance, ultrahigh atomic utilization, and well-defined structure. Beyond single-atom protrusions, two more motifs of single-atom substitutions and single-atom vacancies along with synergistic single-atom motif assemblies have been progressively developed to enrich the single-atom family. On the other hand, besides traditional carbon material based substrates, a wide variety of 2D transitional metal dichalcogenides (TMDs) have been emerging as a promising platform for single-atom catalysis owing to their diverse elemental compositions, variable crystal structures, flexible electronic structures, and intrinsic activities toward many catalytic reactions. Such substantial expansion of both single-atom motifs and substrates provides an enriched toolbox to further optimize the geometric and electronic structures for pushing the performance limit. Concomitantly, higher requirements have been put forward for synthetic and characterization techniques with related technical bottlenecks being continuously conquered. Furthermore, this burgeoning single-atom catalyst (SAC) system has triggered serial scientific issues about their changeable single atom-2D substrate interaction, ambiguous synergistic effects of various atomic assemblies, as well as dynamic structure-performance correlations, all of which necessitate further clarification and comprehensive summary. In this context, this Review aims to summarize and critically discuss the single-atom engineering development in the whole field of 2D TMD based catalysis covering their evolution history, synthetic methodologies, characterization techniques, catalytic applications, and dynamic structure-performance correlations. In situ characterization techniques are highlighted regarding their critical roles in real-time detection of SAC reconstruction and reaction pathway evolution, thus shedding light on lifetime dynamic structure-performance correlations which lay a solid theoretical foundation for the whole catalytic field, especially for SACs.

Molecule-Upgraded van der Waals Contacts for Schottky-Barrier-Free Electronics

The applications of any ultrathin semiconductor device are inseparable from high-quality metal-semiconductor contacts with designed Schottky barriers. Building van der Waals (vdWs) contacts of 2D semiconductors represents an advanced strategy of lowering the Schottky barrier height by reducing interface states, but will finally fail at the theoretical minimum barrier due to the inevitable energy difference between the semiconductor electron affinity and the metal work function. Here, an effective molecule optimization strategy is reported to upgrade the general vdWs contacts, achieving near-zero Schottky barriers and creating high-performance electronic devices. The molecule treatment can induce the defect healing effect in p-type semiconductors and further enhance the hole density, leading to an effectively thinned Schottky barrier width and improved carrier interface transmission efficiency. With an ultrathin Schottky barrier width of ≈2.17 nm and outstanding contact resistance of ≈9 kΩ µm in the optimized Au/WSe₂ contacts, an ultrahigh field-effect mobility of ≈148 cm²  V^-1 s^-1 in chemical vapor deposition grown WSe₂ flakes is achieved. Unlike conventional chemical treatments, this molecule upgradation strategy leaves no residue and displays a high-temperature stability at >200 °C. Furthermore, the Schottky barrier optimization is generalized to other metal-semiconductor contacts, including 1T-PtSe₂ /WSe₂ , 1T'-MoTe₂ /WSe₂ , 2H-NbS₂ /WSe₂ , and Au/PdSe₂ , defining a simple, universal, and scalable method to minimize contact resistance.

Direct Charge Trapping Multilevel Memory with Graphdiyne/MoS2 Van der Waals Heterostructure

Direct charge trapping memory, a new concept memory without any dielectric, has begun to attract attention. However, such memory is still at the incipient stage, of which the charge-trapping capability depends on localized electronic states that originated from the limited surface functional groups. To further advance such memory, a material with rich hybrid states is highly desired. Here, a van der Waals heterostructure design is proposed utilizing the 2D graphdiyne (GDY) which possesses abundant hybrid states with different chemical groups. In order to form the desirable van der Waals coupling, the plasma etching method is used to rapidly achieve the ultrathin 2D GDY with smooth surface for the first time. With the plasma-treated 2D GDY as charge-trapping layer, a direct charge-trapping memory based on GDY/MoS2 is constructed. This bilayer memory is featured with large memory window (90 V) and high degree of modulation (on/off ratio around 8 × 107 ). Two operating mode can be achieved and data storage capability of 9 and 10 current levels can be obtained, respectively, in electronic and opto-electronic mode. This GDY/MoS2 memory introduces a novel application of GDY as rich states charge-trapping center and offers a new strategy of realizing high performance dielectric-free electronics, such as optical memories and artificial synaptic.

349 Improving Assessment of Patients with Suspected Cauda Equina Syndrome Using A Standardised Proforma

Introduction

Cauda Equina Syndrome (CES) has a devastating impact on the life of affected individuals. Most patients are reviewed by doctors who do not have specialist spinal expertise. NHS Lanarkshire guidelines for CES are based on ‘Standards of Care in Cauda Equina Syndrome’ (Todd and Dickson) 2016.

Method

Documented assessment of a sample of patients with suspected CES in our hospital was audited against standards set in regional guidelines. A tick-box proforma was introduced to standardise assessment, with re-audit thereafter. Chi-squared was used for statistical analysis.

Results

Cycle 1 (2018): Documented assessment of findings in 30 patients - bilateral radiculopathy (80%), urinary incontinence (93%), faecal incontinence (73%), anal tone (93%), saddle anaesthesia (83%), bladder volumes (90%) and ASIA chart (20%).

Cycle 2 (2019): Documented assessment of above findings was 100% in patients where a proforma was used. Proforma was used in 81% of patients.

Conclusions

Use of a standardised proforma improved assessment of CES. There was a statistically significant improvement in use of an ASIA chart (P &lt; 0.01) and assessment of faecal incontinence (P = 0.039). Compliance with use of this proforma could be improved further, to enhance patient care. Following the success of the proforma, it is being reviewed for implementation on a regional level.

Fully Organic Self-Powered Electronic Skin with Multifunctional and Highly Robust Sensing Capability

Electronic skin (e-skin) with skin-like flexibility and tactile sensation will promote the great advancements in the fields of wearable equipment. Thus, the multifunction and high robustness are two important requirements for sensing capability of the e-skin. Here, a fully organic self-powered e-skin (FOSE-skin) based on the triboelectric nanogenerator (TENG) is developed. FOSE-skin based on TENG can be fully self-healed within 10 hours after being sheared by employing the self-healing polymer as a triboelectric layer and ionic liquid with the temperature sensitivity as an electrode. FOSE-skin based on TENG has the multifunctional and highly robust sensing capability and can sense the pressure and temperature simultaneously. The sensing capability of the FOSE-skin based on TENG can be highly robust with no changes after self-healing. FOSE-skin based on TENG can be employed to detect the arm swing, the temperature change of flowing water, and the motion trajectory. This work provides a new idea for solving the issues of monofunctional and low robust sensing capability for FOSE-skin based on TENG, which can further promote the application of wearable electronics in soft robotics and bionic prosthetics.

Near-ideal van der Waals rectifiers based on all-two-dimensional Schottky junctions

The applications of any two-dimensional (2D) semiconductor devices cannot bypass the control of metal-semiconductor interfaces, which can be severely affected by complex Fermi pinning effects and defect states. Here, we report a near-ideal rectifier in the all-2D Schottky junctions composed of the 2D metal 1 T'-MoTe2 and the semiconducting monolayer MoS2. We show that the van der Waals integration of the two 2D materials can efficiently address the severe Fermi pinning effect generated by conventional metals, leading to increased Schottky barrier height. Furthermore, by healing original atom-vacancies and reducing the intrinsic defect doping in MoS2, the Schottky barrier width can be effectively enlarged by 59%. The 1 T'-MoTe2/healed-MoS2 rectifier exhibits a near-unity ideality factor of ~1.6, a rectifying ratio of >5 × 105, and high external quantum efficiency exceeding 20%. Finally, we generalize the barrier optimization strategy to other Schottky junctions, defining an alternative solution to enhance the performance of 2D-material-based electronic devices.

Hidden Vacancy Benefit in Monolayer 2D Semiconductors

Monolayer 2D semiconductors (e.g., MoS₂ ) are of considerable interest for atomically thin transistors but generally limited by insufficient carrier mobility or driving current. Minimizing the lattice defects in 2D semiconductors represents a common strategy to improve their electronic properties, but has met with limited success to date. Herein, a hidden benefit of the atomic vacancies in monolayer 2D semiconductors to push their performance limit is reported. By purposely tailoring the sulfur vacancies (SVs) to an optimum density of 4.7% in monolayer MoS₂ , an unusual mobility enhancement is obtained and a record-high carrier mobility (>115 cm² V^-1 s^-1 ) is achieved, realizing monolayer MoS₂ transistors with an exceptional current density (>0.60 mA µm^-1 ) and a record-high on/off ratio >10¹⁰ , and enabling a logic inverter with an ultrahigh voltage gain >100. The systematic transport studies reveal that the counterintuitive vacancy-enhanced transport originates from a nearest-neighbor hopping conduction model, in which an optimum SV density is essential for maximizing the charge hopping probability. Lastly, the vacancy benefit into other monolayer 2D semiconductors is further generalized; thus, a general strategy for tailoring the charge transport properties of monolayer materials is defined.

Strain Engineering in 2D Material-Based Flexible Optoelectronics

Flexible optoelectronics, as promising components hold shape-adaptive features and dynamic strain response under strain engineering for various intelligent applications. 2D materials with atomically thin layers are ideal for flexible optoelectronics because of their high flexibility and strain sensitivity. However, how the strain affects the performance of 2D materials-based flexible optoelectronics is confused due to their hypersensitive features to external strain changes. It is necessary to establish an evaluation system to comprehend the influence of the external strain on the intrinsic properties of 2D materials and the photoresponse performance of their flexible optoelectronics. Here, a focused review of strain engineering in 2D materials-based flexible optoelectronics is provided. The first attention is on the mechanical properties and the strain-engineered electronic properties of 2D semiconductors. An evaluation system with relatively comprehensive parameters in functionality and service capability is summarized to develop 2D materials-based flexible optoelectronics in practical application. Based on the parameters, some strategies to improve the functionality and service capability are proposed. Finally, combining with strain engineering in future intelligence devices, the challenges and future perspective developing 2D materials-based flexible optoelectronics are expounded.

Malnutrition Prolongs the Hospitalization of Patients with COVID-19 Infection: A Clinical Epidemiological Analysis

OBJECTIVES

During the 2019 coronavirus disease (COVID-19) outbreak, malnutrition may contribute to COVID-19 adverse outcomes. We conducted a clinical epidemiological analysis to investigate the association of malnutrition with hospitalized duration in patients with COVID-19.

DESIGN

Retrospective survey study.

SETTING

Taikang Tongji (Wuhan) hospital in Wuhan, China.

PARTICIPANTS

139 patients with COVID-19.

METHODS

In total, 139 patients with COVID-19 from patients in the Infection Department of Taikang Tongji (Wuhan) hospital from February 2020 to April 2020 were analyzed retrospectively. We used the "Global leadership Initiative on Malnutrition(GLIM)" assessment standard published in 2019 to assess nutritional status. Prolonged hospitalization was lasting more than the median value of the hospitalized days (17 days) in this population.

RESULTS

According to the assessment results of GLIM nutrition assessment, the patients were divided into malnutrition group and normal nutrition group. Compared with the patients in the normal nutrition group, the hospitalization time was longer(15.67±6.26 days versus 27.48±5.04 days, P = 0.001). Kaplan-Meier analysis showed patients with malnutrition were more likely to be hospitalized longer compared with those normal nutrition (mean with 95% confidence interval [CI]: 28.91[27.52-30.30] versus 22.78[21.76-23.79], P = 0.001). COX regression analysis showed that malnutrition (hazard ratio [HR] = 3.773, P for trend = 0.001) was proportional associated with being discharged from hospital delayed.

CONCLUSION AND IMPLICATIONS

Present findings suggested that malnutrition contributed to predicting a probability of prolonged hospitalization in patients with COVID-19 infection, to whom extra attentions and precautions should be paid during clinical treatments. Based on the existing results, it is recommended that inpatients with nutritional risk or malnutrition start nutritional support treatment as soon as possible.

Atomic-Thin ZnO Sheet for Visible-Blind Ultraviolet Photodetection

The atomic-thin 2D semiconductors have emerged as plausible candidates for future optoelectronics with higher performance in terms of the scaling process. However, currently reported 2D photodetectors still have huge shortcomings in ultraviolet and especially visible-blind wavelengths. Here, a simple and nontoxic surfactant-assisted synthesis strategy is reported for the controllable growth of atomically thin (1.5 to 4 nm) ZnO nanosheets with size ranging from 3 to 30 µm. Benefit from the short carbon chains and the water-soluble ability of sodium dodecyl sulfate (SDS), the synthesized ZnO nanosheets possess high crystal quality and clean surface, leading to good compatibility with traditional micromanufacturing technology and high sensitivity to UV light. The photodetectors constructed with ZnO demonstrate the highest responsivity (up to 2.0 × 10⁴ A W^-1 ) and detectivity (D* = 6.83 × 10¹⁴ Jones) at a visible-blind wavelength of 254 nm, and the photoresponse speed is optimized by the 400 °C annealing treatment (τ_R  = 3.97 s, τ_D  = 5.32 s), thus the 2D ZnO can serve as a promising material to fill in the gap for deep-UV photodetection. The method developed here opens a new avenue to controllably synthesize 2D nonlayered materials and accelerates their applications in high-performance optoelectronic devices.

Immunocyte density in parathyroid carcinoma is correlated with disease relapse

PURPOSE

Parathyroid carcinoma (PC) is an endocrine malignancy with a poor prognosis. The tumour immune microenvironment is a critical factor influencing the outcomes of multiple cancer types. However, knowledge of the immune microenvironment in PC remains limited.

METHODS

The intratumoural density of immunocytes and the Ki-67 index were evaluated immunohistochemically in 51 PC patient samples and were compared with clinicopathological features and parafibromin staining results. The Kaplan-Meier method and Cox proportional hazards analysis were used to estimate the effects of these variables on clinical outcomes.

RESULTS

Intratumoural immunocyte density was not correlated with age, gender, urolithiasis, or palpation of a neck mass. The Ki-67 index was correlated with the intratumoural density of CD3⁺ cells (P = 0.022) and CD8⁺ cells (P = 0.021) and serum calcium levels (P = 0.022). In the intratumoural area of primary foci, Kaplan-Meier method showed that the risk factors associated with recurrence/metastasis were a low density of CD3⁺ (P = 0.017), CD8⁺ (P = 0.019) and CD45⁺ cells (P = 0.047), a high density of CD163⁺ cells (P = 0.003) and a high Ki-67 index (P = 0.004). Cox regression multivariate analysis revealed that CD163⁺ cell density (hazard ratio (HR) 16.19, 95% confidence interval (CI) 1.99-131.66; P = 0.009) and CD8⁺ cell density (HR 0.13, 95% CI 0.02-0.76, P = 0.024) were independent factors associated with PC relapse.

CONCLUSION

The immune microenvironment is an important factor influencing the relapse of PC. The intratumoural density of CD3⁺, CD8⁺, CD45⁺, and CD163⁺ immunocytes was correlated with disease-free survival (DFS) in patients with PC. Immunotherapy based on T lymphocytes or tumour-associated macrophages may be a promising treatment strategy.

Highly Robust and Self-Powered Electronic Skin Based on Tough Conductive Self-Healing Elastomer

Self-powered electronic skin (E-skin) can be endowed with high robustness by employing self-healing materials. However, most self-powered E-skin employs two heterogeneous materials with high modulus mismatch at the interface and poor fully self-healing ability, which reduces the robustness of the whole device. Here, a conductive polyurethane elastomer (PUE) with excellent mechanical toughness and self-healing ability is prepared. Based on the self-healing insulated/conductive PUE homogeneous structure and triboelectric-electrostatic induction effect, a highly robust and self-powered E-skin (HRSE-skin) is developed. The HRSE-skin possesses stable mechanosensation capability during the 50% stretching deformation due to a low modulus mismatch in the homogeneous structure. In addition, the stretchability and mechanosensation capability of the HRSE-skin can be restored after the fracture owing to the fully self-healing ability of the homogeneous structure. Therefore, the HRSE-skin has high robustness of the whole device including stable service behaviors and excellent restorability. The developed HRSE-skin demonstrates high robustness in the detection of the force and bending angle of the prosthetic joint. This work solves the low robustness of self-powered E-skin by the preparation of conductive self-healing PUE and the construction of the homogeneous structure, which is important for the practical applications of self-powered E-skin in prosthetic limbs and advanced robotics.

Graphdiyne: Bridging SnO2 and Perovskite in Planar Solar Cells

The matching of charge transport layer and photoactive layer is critical in solar energy conversion devices, especially for planar perovskite solar cells based on the SnO₂ electron-transfer layer (ETL) owing to its unmatched photogenerated electron and hole extraction rates. Graphdiyne (GDY) with multi-roles has been incorporated to maximize the matching between SnO₂ and perovskite regarding electron extraction rate optimization and interface engineering towards both perovskite crystallization process and subsequent photovoltaic service duration. The GDY doped SnO₂ layer has fourfold improved electron mobility due to freshly formed C-O σ bond and more facilitated band alignment. The enhanced hydrophobicity inhibits heterogeneous perovskite nucleation, contributing to a high-quality film with diminished grain boundaries and lower defect density. Also, the interfacial passivation of Pb-I anti-site defects has been demonstrated via GDY introduction.

Self-powered user-interactive electronic skin for programmable touch operation platform

User-interactive electronic skin is capable of spatially mapping touch via electric readout and providing visual output as a human-readable response. However, the high power consumption, complex structure, and high cost of user-interactive electronic skin are notable obstacles for practical application. Here, we report a self-powered, user-interactive electronic skin (SUE-skin), which is simple in structure and low in cost, based on a proposed triboelectric-optical model. The SUE-skin achieves the conversion of touch stimuli into electrical signal and instantaneous visible light at trigger pressure threshold as low as 20 kPa, without external power supply. By integrating the SUE-skin with a microcontroller, a programmable touch operation platform was built that can recognize more than 156 interaction logics for easy control of consumer electronics. This cost-effective technology has potential relevance to gesture control, augmented reality, and intelligent prosthesis applications.

Point defect induced intervalley scattering for the enhancement of interlayer electron transport in bilayer MoS2 homojunctions

Since the emergence of transition metal dichalcogenide (TMDC) based van der Waals (vdW) structures, interlayer charge transport has become an important issue towards the application of these novel materials. Due to the unique layered structure of these materials, charge transport across the vdW gaps via tunneling is governed by individual valleys with different interlayer coupling strengths. On the other hand, the omnipresent point defects in TMDCs could possibly cause intervalley scattering between these valleys. In this article, we investigate the influence of point defect induced intervalley scattering on the interlayer charge transport of the MoS2 homojunction by first principles calculation. We find that S vacancies and Mo-S antisite defects enhance the electron interlayer transport by intervalley scattering that divert the electrons from the non-interlayer coupling K valley to the strong interlayer coupling Q valley. The interlayer charge transport enhancement caused by such an intervalley scattering mechanism could pave the way towards understanding the interlayer charge transport in TMDC based vdW structures.

Cost-effectiveness of bivalent versus monovalent vaccines against hand, foot and mouth disease

OBJECTIVES

Enterovirus 71 (EV71) and coxsackievirus A16 (CA16) were responsible for 43.3% (235 123/543 243) and 24.8% (134 607/543 243) of all laboratory-confirmed hand, foot and mouth disease (HFMD) cases during 2010-2015 in China. Three monovalent EV71 vaccines have been licensed in China while bivalent EV71/CA16 vaccines are under development. A comparative cost-effectiveness analysis of bivalent EV71/CA16 versus monovalent EV71 vaccination would be useful for informing the additional value of bivalent HFMD vaccines in China.

METHODS

We used a static model parameterized with the national HFMD surveillance data during 2010-2013, virological HFMD surveillance records from all 31 provinces in mainland China during 2010-2013 and caregiver survey data of costs and health quality of life during 2012-2013. We estimated the threshold vaccine cost (TVC), defined as the maximum additional cost that could be paid for a cost-effective bivalent EV71/CA16 vaccine over a monovalent EV71 vaccine, as the outcome. The base case analysis was performed from a societal perspective. Several sensitivity analyses were conducted by varying assumptions governing HFMD risk, costs, discounting and vaccine efficacy.

RESULTS

In the base case, choosing the bivalent EV71/CA16 over monovalent EV71 vaccination would be cost-effective only if the additional cost of the bivalent EV71/CA16 compared with the monovalent EV71 vaccine is less than €4.7 (95% CI 4.2-5.2). Compared with the TVC in the base case, TVC increased by up to €8.9 if all the test-negative cases were CA16-HFMD; decreased by €1.1 with an annual discount rate of 6% and exclusion of the productivity loss; and increased by €0.14 and €0.3 with every 1% increase in bivalent vaccine efficacy against CA16-HFMD and differential vaccine efficacy against EV71-HFMD, respectively.

CONCLUSIONS

Bivalent EV71/CA16 vaccines can be cost-effective compared with monovalent EV71 vaccines, if suitably priced. Our study provides further evidence for determining the optimal use of HFMD vaccines in routine paediatric vaccination programme in China.

Single-Atom Vacancy Defect to Trigger High-Efficiency Hydrogen Evolution of MoS2

Defect engineering is widely applied in transition metal dichalcogenides (TMDs) to achieve electrical, optical, magnetic, and catalytic regulation. Vacancies, regarded as a type of extremely delicate defect, are acknowledged to be effective and flexible in general catalytic modulation. However, the influence of vacancy states in addition to concentration on catalysis still remains vague. Thus, via high throughput calculations, the optimized sulfur vacancy (S-vacancy) state in terms of both concentration and distribution is initially figured out among a series of MoS₂ models for the hydrogen evolution reaction (HER). In order to realize it, a facile and mild H₂O₂ chemical etching strategy is implemented to introduce homogeneously distributed single S-vacancies onto the MoS₂ nanosheet surface. By systematic tuning of the etching duration, etching temperature, and etching solution concentration, comprehensive modulation of the S-vacancy state is achieved. The optimal HER performance reaches a Tafel slope of 48 mV dec^-1 and an overpotential of 131 mV at a current density of 10 mA cm^-2, indicating the superiority of single S-vacancies over agglomerate S-vacancies. This is ascribed to the more effective surface electronic structure engineering as well as the boosted electrical transport properties. By bridging the gap, to some extent, between precise design from theory and practical modulation in experiments, the proposed strategy extends defect engineering to a more sophisticated level to further unlock the potential of catalytic performance enhancement.