Exciton-Driven and Layer-Independent Linear and Nonlinear Optical Properties in NbOCl2.

We investigate the electronic structure and linear and nonlinear [second-harmonic generation (SHG)] spectra of the NbOCl2 monolayer, bilayer, and bulk by using a real-time first-principles approach based on many-body theory. First, the interlayer couplings between NbOCl2 layers are very weak, due to the relatively large interlayer distance, saturation of the p orbital of Cl atoms, and high degree of localization of charge density around the Nb atom for both the lowest conduction band and the highest valence band. Second, the quasiparticle gaps and exciton binding energy for the three systems show layer-dependent features and decrease with an increase in layer thickness. Most importantly, the linear and SHG spectra of the NbOCl2 monolayer, bilayer, and bulk are dominated by strong excitonic resonances and exhibit layer-independent features due to the weak interlayer couplings. Our findings demonstrate that excitonic effects should be included in studying the optical properties of not only two-dimensional materials but also layered bulk materials with weak interlayer couplings.

Extending the Charge Carrier Recombination Lifetime by Octahedral Rotations in Ruddlesden-Popper Ba3Zr2S7 Perovskites.

Intentional distortions of [BX6] octahedra within perovskite structures have been recognized as a potent strategy for precise band gap adjustments and optimization of their photovoltaic properties, yet information regarding charge carrier dynamics linked to octahedral distortion under ambient conditions for chalcogenide perovskites remains limited. In this study, we utilize ab initio nonadiabatic molecular dynamics to explore the dynamics of photogenerated carriers in a representative two-dimensional Ba3Zr2S7 material in the Ruddlesden-Popper phase. The theoretical results highlight the influence of octahedral rotation on the materials' stability and carrier recombination lifetime of the system. Specifically, the octahedrally rotating P42/mnm phase exhibits a prolonged nonradiative carrier recombination lifetime attributed to the stabilized electron-phonon coupling. These findings offer valuable insights into the fundamental physical characteristics of imposed octahedral distortion and its potential for optimizing the optoelectronic performance of 2D Ruddlesden-Popper Ba-Zr-S chalcogenide materials.

Two-dimensional half-metals MSi2N4 (M = Al, Ga, In, Tl) with intrinsic p-type ferromagnetism and ultrawide bandgaps.

Intrinsic half-metallic nanomaterials with 100% spin polarization are highly demanded for next-generation spintronic devices. Here, by using first-principles calculations, we have designed a class of new two-dimensional (2D) p-type half-metals, MSi2N4 (M = Al, Ga, In and Tl), which show high mechanical, thermal and dynamic stabilities. MSi2N4 not only have ultrawide electronic bandgaps for spin-up channels in the range of 4.05 to 6.82 eV but also have large half-metallic gaps in the range of 0.75 to 1.47 eV, which are large enough to prevent the spin-flip transition. The calculated magnetic moment is 1 µB per cell, resulting from polarized N1-px/py orbitals. Moreover, MSi2N4 possess robust long-range ferromagnetic orderings with Curie temperatures in the range of 35-140 K, originating from the interplay of N1-M-N1 superexchange interactions. Furthermore, spin dependent electronic transport calculations reveal 100% spin polarization. Our results highlight new promising 2D ferromagnetic half-metals toward future spintronic applications.

Investigation of nonlinear optical properties in α-A2BB'O6 (A = Li, Na, K; B = Ti, Zr, Hf; B' = Se, Te) by first-principles calculations.

Nonlinear optical (NLO) crystals based on oxides typically have wide bandgaps and large laser damage thresholds (LDTs), which are important for generating high-power and continuous terahertz radiation. Recently, a new family of NLO materials α-A2BB'O6 including Li2TiTeO6 (LTTO) with a strong second harmonic generation (SHG) efficiency of 26 × KH2PO4 (KDP) and a large LDT of 550 MW cm-2 were reported. Herein, we systematically study the electronic structures and NLO properties of α-A2BB'O6 (A = Li, Na, K; B = Ti, Zr, Hf; B' = Se, Te) to explore the relationship between the structure and SHG coefficient. First, 15 members of the A2BB'O6 family are demonstrated to be highly stable and NLO materials, excluding K2TiTeO6, K2TiSeO6 and K2ZrSeO6. Then, the electronic band structure, dipole moment and distortion of BO6/B'O6 octahedrons, SHG coefficient and terahertz absorption spectrum are calculated comprehensively with the element variation of A-site, B-site and B'-site. Finally, the magnitude of the SHG coefficient is found to be directly proportional to the value of total dipole moment and distortion, and inversely proportional to the bandgap value. Most importantly, among the A2BB'O6 materials, K2HfSeO6 shows the smallest direct bandgap of 2.99 eV, the largest SHG coefficient d33 of about 5 × LTTO and low terahertz absorbance from 0.1 to 9 THz. Our results provide new NLO crystals that may have potential application in terahertz radiation sources and other nonlinear electronics.

Synthesis of MnOOH and its application in a supporting hexagonal Pd/C catalyst for the oxygen reduction reaction.

With the expansion of global energy problems and the deepening of research on oxygen reduction reaction (ORR) in alkaline media, the development of low cost and high electrocatalytic performance catalysts has become a research hotspot. In this study, a hexagonal Pd-C-MnOOH composite catalyst was prepared by using the triblock copolymer P123 as the reducing agent and protective agent, sucrose as the carbon source and self-made MnOOH as the carrier under hydrothermal conditions. When the Pd load is 20% and the C/MnOOH ratio is 1 : 1, the 20% Pd-C-MnOOH-1 : 1 catalyst obtained by the one-step method has the highest ORR activity and stability in the alkaline system. At 1600 rpm, the limiting diffusion current density and half-wave potential of the 20% Pd-C-MnOOH-1 : 1 electrocatalyst are -4.78 mA cm-2 and 0.84 V, respectively, which are better than those of the commercial 20%Pd/C catalyst. According to the Koutecky-Levich (K-L) equation and the linear fitting results, the electron transfer number of the 20%Pd-C-MnOOH-1 : 1 electrocatalyst for the oxygen reduction reaction is 3.8, which is similar to that of a 4-electron process. After 1000 cycles, the limiting diffusion current density of the 20%Pd-C-MnOOH-1 : 1 catalyst is -4.61 mA cm-2, which only decreases by 3.7%, indicating that the 20%Pd-C-MnOOH-1 : 1 catalyst has good stability. The reason for the improvement of the ORR performance of the Pd-C-MnOOH composite catalyst is the improvement of the conductivity of the carbon layer formed by original carbonization, the regular hexagonal highly active Pd particles and the synergistic catalytic effect between Pd and MnOOH. The method of introducing triblock copolymers in the synthesis of oxides and metal-oxide composite catalysts is expected to be extended to other electrocatalysis fields.

Exploration of the origin of the excellent charge-carrier dynamics in Ruddlesden-Popper oxysulfide perovskite Y2Ti2O5S2.

Although the efficient separation of electron-hole (e-h) pairs is one of the most sought-after electronic characteristics of materials, due to thermally induced atomic motion and other factors, they do not remain separated during the carrier transport process, potentially leading to rapid carrier recombination. Here, we utilized real-time time-dependent density functional theory in combination with nonadiabatic molecular dynamics (NAMD) to explore the separated dynamic transport path within Ruddlesden-Popper oxysulfide perovskite Y2Ti2O5S2 caused by the dielectric layer and phonon frequency difference. The underlying origin of the efficient overall water splitting in Y2Ti2O5S2 is systematically explored. We report the existence of the bi-directional e-h separate-path transport, in which, the electrons transport in the Ti2O5 layer and the holes diffuse in the rock-salt layer. This is in contrast to the conventional e-h separated distribution with a crowded transport channel, as observed in SrTiO3 and hybrid perovskites. Such a unique feature finally results in a long carrier lifetime of 321 ns, larger than that in the SrTiO3 perovskite (160 ns) with only one carrier transport channel. This work provides insights into the carrier transport in lead-free perovskites and yields a novel design strategy for next-generation functionalized optoelectronic devices.

Theoretical Dissection of Cation-Deficient Layered Ruddlesden-Popper Oxysulfide Perovskites with a High-Efficiency Carrier Transport Channel.

The search for lead-free perovskite materials has triggered intensive interest. Here, we study the electronic structures and optical properties of cation-deficient Ruddlesden-Popper oxysulfide perovskites Ln2Ti2O5S2 (Ln = Sc, Y, or La), with a tunable band gap of 1.45-2.1 eV and a small exciton binding energy of ∼0.1 eV, among which Y2Ti2O5S2 has been synthesized experimentally. Sc2Ti2O5S2 possesses the largest light absorbance in the visible region. We further rationalize the light absorption via the transition dipole moment and suggest potential applications of Sc2Ti2O5S2 in solar cells and Y2Ti2O5S2 and La2Ti2O5S2 in water splitting. In addition, this family exhibits small effective masses within the x-y plane and large ones along the z direction. Most importantly, electron gas-like carrier behaviors are observed within the Ti-O bond region, offering a diffusion channel for electron transport. These findings greatly advance our understanding of lead-free perovskites and offer a novel material platform for future optoelectronic devices.

Highly lithiophilic and structurally stable Cu-Zn alloy skeleton for high-performance Li-rich ternary anodes.

Lithium (Li)-rich ternary alloy, comprising a multi-alloy phase as the built-in three-dimensional (3D) framework and a Li metal phase as a reversible Li reservoir, is a promising high-energy-density anode for rechargeable Li metal batteries. The introduction of metal/metalloid components to the alloy can effectively regulate Li deposition and maintain the dimensional integrity of the Li anode. Herein, the lithium-copper-zinc (Li-Cu-Zn) ternary alloy, as a new type of alloy anode, is synthesized via a facile thermal melting method. The fully delithiated 3D scaffold comprised two Cu-Zn alloy phases named CuZn and CuZn5. These alloy phases exhibit higher lithiophilicity and structural stability than Li-Zn and Li-Cu alloys. Moreover, the CuZn phase is electrochemically inert, ensuring the geometric stability of the anode, while the CuZn5 phase can readily undergo alloying reaction with Li to form the LiZn phase, thereby facilitating uniform Li nucleation and deposition. The hybridized multiphase alloy structure and specific energy storage mechanism of the Cu-Zn based alloy scaffold in the ternary alloy anode facilitate dendrite-free Li deposition and prolonged cycle lifetime. The Li metal full battery based on lithium iron phosphate (LiFePO4) cathode exhibits high cycling stability with high-capacity retention of 95.4% after 1000 cycles at 1C.

A novel phase of superionic conductor ß'-Na3PS4 with a large band gap and a low migration barrier.

Na3PS4 crystals with high ionic conductivity are promising solid-state electrolytes. Here, a novel phase of Na3PS4 (ß'-NPS) crystallizing in a cubic lattice with a space group of P4̄3m was systematically investigated using first-principles calculations. First of all, ß'-NPS is determined to be thermodynamically, dynamically and mechanically stable. The phase transition from tetragonal Na3PS4(α-NPS) to a cubic ß'-NPS system occurs at approximately 480 K, suggesting high feasibility of experimental access. Moreover, the ß'-NPS is an insulator with a large band gap of 4.05 eV and a low migration energy barrier of 0.10 eV for an interstitial Na ion. Significantly, a novel Na ion diffusion mechanism, that is, interstitial diffusion, is proposed, in contrast to traditional vacancy diffusion or kick-off diffusion as observed in most solid electrolytes. This work proposes ß'-NPS as a promising superionic conductor for sodium ion batteries and provides theoretical guidance towards designing future ideal solid-state electrolytes.

An extremum-guided interpolation for sparsely sampled photoacoustic imaging.

In photoacoustic (PA) reconstruction, spatial constraints or real-time system requirements often result to sparse PA sampling data. For sparse PA sensor data, the sparse spatial and dense temporal sampling often leads to poor signal continuity. To address the structural characteristics of sparse PA signals, a data interpolation algorithm based on extremum-guided interpolation is proposed. This algorithm is based on the continuity of the signal, and can complete the estimation of high sampling rate signals without complex mathematical calculations. PA signal data is interpolated and reconstructed, and the results are evaluated using image quality assessment methods. The simulation and experimental results show that the proposed method performs better than several typical algorithms, effectively restoring image details, suppressing the generation of artifacts and noise, and improving the quality of PA reconstruction under sparse sampling.

Understanding Trends in Electrochemical Methanol Oxidation Reaction Activity on a Single Transition-Metal Atom Embedded in N-Coordinated Graphene Catalysts.

The lack of efficient catalysts and research on the mechanism for the methanol oxidation reaction (MOR) impedes the development of direct methanol fuel cells. In this work, based on density functional theory calculations, we systematically investigated the activity trends of electrochemical MOR on a single transition-metal atom embedded in N-coordinated graphene (M@N4C). By calculating the free energy diagrams of MOR on M@N4C, Co@N4C was screened out to be the most effective MOR catalyst with a low limiting potential of 0.41 V due to the unique charge transfers and electronic structures. Importantly, one- and two-dimensional volcano relationships in MOR on M@N4C catalysts are established based on the d-band center and the Gibbs free energy of ΔG*CH3OH and ΔG*CO, respectively. In one word, this work provides theoretical guides toward the improved activity of MOR on M@N4C and hints for the design of active and efficient MOR electrocatalysts.

Two-Dimensional Octuple-Atomic-Layer M2Si2N4 (M = Al, Ga and In) with Long Carrier Lifetime.

Bulk III-nitride materials MN (M = Al, Ga and In) and their alloys have been widely used in high-power electronic and optoelectronic devices, but stable two-dimensional (2D) III-nitride materials, except h-BN, have not been realized yet. A new kind of 2D III-nitride material M2Si2N4 (M = Al, Ga and In) is predicted by choosing Si as the appropriate passivation element. The stability, electronic and optical properties of 2D M2Si2N4 materials are studied systematically based on first-principles calculations. The results show that Al2Si2N4 and Ga2Si2N4 are found to be indirect bandgap semiconductors, while In2Si2N4 is a direct bandgap semiconductor. Moreover, Al2Si2N4 and In2Si2N4 have good absorption ability in the visible light region, while Ga2Si2N4 is an ultraviolet-light-absorbing material. Furthermore, the carrier lifetimes of Ga2Si2N4 and In2Si2N4 are as large as 157.89 and 103.99 ns, respectively. All these desirable properties of M2Si2N4 materials make them attractive for applications in electronics and photoelectronics.

Comparison of spectral-domain optical coherence tomography parameters between the eyes of anisometropic amblyopia children and normal eyes / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To compare the thickness of retina in macular area and retinal nerve fiber layer(RNFL)around optic disc between the eyes of monocular anisometropic amblyopia children and normal eyes.METHODS: A total of 62 children(124 eyes)with monocular anisometropic amblyopia who were treated in Chengdu Women's and Children's Central Hospital from January 2021 to October 2022 were selected as the experimental group, and 60 children(60 eyes; right eye)with normal vision who were treated in the same period were selected as the control group. Spectral-domain optical coherence tomography(SD-OCT)was used to detect the retinal thickness in macular region and the RNFL thickness around optic disc in the two groups, and comparative analysis was performed.RESULTS: The retinal thickness and perioptic RNFL thickness of amblyopic children in experimental group were thicker than those in control group, and most of them had significant differences(P<0.05). The retinal thickness and perioptic RNFL thickness of contralateral non-amblyopic children in experimental group were thinner than those in control group, but there were no significant differences in most of them(P>0.05).CONCLUSIONS: There are differences in the retinal thickness of the macula and perioptic RNFL in the amblyopic eye and the contralateral non-amblyopic eye of monocular anisometropic amblyopic children compared with normal eyes, and the contralateral non-amblyopic eye is not completely equal to the normal eye.

Visualization method of type Ⅳ pili and its application in the study of pili function / 生物工程学报

As an important protein structure on the surface of bacteria, type Ⅳ pili (TFP) is the sensing and moving organ of bacteria. It plays a variety of roles in bacterial physiology, cell adhesion, host cell invasion, DNA uptake, protein secretion, biofilm formation, cell movement and electron transmission. With the rapid development of research methods, technical equipment and pili visualization tools, increasing number of studies have revealed various functions of pili in cellular activities, which greatly facilitated the microbial single cell research. This review focuses on the pili visualization method and its application in the functional research of TFP, providing ideas for the research and application of TFP in biology, medicine and ecology.

A multilevel model analysis of the association between reading and writing posture with myopia in primary and secondary school students / 中国学校卫生

Objective@#To explore the association between reading and writing posture with the occurrence of myopia in Chinese children and adolescents, so as to provide a reference for reducing its prevalence among primary and secondary school students.@*Methods@#Using data from the 2020 survey on the current status of hyperopia reserve in primary and secondary school students from six provinces/cities, namely Beijing, Zhejiang, Chongqing, Shaanxi, Liaoning, and Henan selected by multi stage stratified cluster probability sampling method during November 2020 to June 2022. A total 16 782 students who completed the optometry examination of cycloplegia according to the Children and Adolescents Myopia Screening Standard and questionnaire survey were included for analyzing analyze the association between reading and writing posture with myopia.@*Results@#The overall detection rate of myopia among primary and secondary school students was 45.7%, of which 35.0% were primary school students, 84.1% junior high school students, and 90.4% senior high school students. Poor reading and writing posture was found in 73.6% of primary and secondary school students. Adjusting for confounding factors such as gender, school period, region, outdoor time every day, and whether parents were myopic, the results of the multilevel Logistic regression showed that the following factors were positively correlated with myopia:poor reading and writing posture ( OR=1.17, 95%CI =1.07-1.28), never/occasionally reading and writing with a reading distance which was more than one foot away between the eyes and book ( OR=1.28, 95%CI=1.08-1.53, OR=1.23, 95%CI = 1.08- 1.40), teachers occasionally reminding the child of their reading and writing posture ( OR=1.13, 95%CI =1.01-1.25), and often/always reading and writing while lying down or with the face on the arm ( OR=1.15, 95%CI=1.01-1.32, OR=1.46, 95% CI = 1.17-1.82), always reading and writing with the head in the hand ( OR=1.56, 95%CI =1.20-2.01). Further, a negative correlation was detected between myopia and parents occasionally reminding their children of their reading and writing posture ( OR= 0.85 , 95%CI =0.76-0.96) ( P <0.05).@*Conclusion@#Poor reading and writing posture is a risk factor for the development of myopia in primary and secondary school students, and interventions for reading and writing posture need to be strengthened to reduce the occurrence of myopia among primary and secondary school students.

Effects of specimen preservation and transportation on blood paraquat concentration in rats / 中华劳动卫生职业病杂志

Objective: To investigate the effects of duration, temperature and shake on paraquat (PQ) concentration in the blood of PQ-exposed rats during the specinen preservation and transportation. Methods: In March 2021, 60 SD male rats of Specific Pathogen Free class were randomly divided into low-dose group (10 mg/kg PQ) and high-dose group (80 mg/kg PQ). Each group was divided into 5 subgroups (normal temperature group, cold storage group, 37 ℃ storage group, shaking on normal temperature group and shaking on 37 ℃ group), six rats in each subgroup. The rats were given intraperitoneal injection of PQ, 1 h after exposure, the blood samples were obtained by cardiac extraction. After different interventions, the concentrations of PQ were detected and compared before and after the intervention in each subgroup. Results: In the shaking on 37 ℃ group, the results of PQ concentrations in PQ-exposed rats were significantly lower than those before the intervention (P<0.05). In the other subgroups, the results were not significantly different compared with before intervention (P>0.05) . Conclusion: The concentration of PQ in the blood of rats exposed to PQ was decreased by shaking for 4 hours at 37 ℃.

Clinical application of plasma exchange combined with continuous veno-venous hemofiltration dialysis in children with refractory Kawasaki disease shock syndrome / 中国当代儿科杂志

OBJECTIVES@#To study the role of plasma exchange combined with continuous blood purification in the treatment of refractory Kawasaki disease shock syndrome (KDSS).@*METHODS@#A total of 35 children with KDSS who were hospitalized in the Department of Pediatric Intensive Care Unit, Hunan Children's Hospital, from January 2019 to August 2022 were included as subjects. According to whether plasma exchange combined with continuous veno-venous hemofiltration dialysis was performed, they were divided into a purification group with 12 patients and a conventional group with 23 patients. The two groups were compared in terms of clinical data, laboratory markers, and prognosis.@*RESULTS@#Compared with the conventional group, the purification group had significantly shorter time to recovery from shock and length of hospital stay in the pediatric intensive care unit, as well as a significantly lower number of organs involved during the course of the disease (P<0.05). After treatment, the purification group had significant reductions in the levels of interleukin-6, tumor necrosis factor-α, heparin-binding protein, and brain natriuretic peptide (P<0.05), while the conventional group had significant increases in these indices after treatment (P<0.05). After treatment, the children in the purification group tended to have reductions in stroke volume variation, thoracic fluid content, and systemic vascular resistance and an increase in cardiac output over the time of treatment.@*CONCLUSIONS@#Plasma exchange combined with continuous veno-venous hemofiltration dialysis for the treatment of KDSS can alleviate inflammation, maintain fluid balance inside and outside blood vessels, and shorten the course of disease, the duration of shock and the length of hospital stay in the pediatric intensive care unit.

Diagnosis of a patient with Spinocerebellar ataxia type 29 due to a novel variant of ITPR1 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of a child with spinocerebellar ataxia type 29 (SCA29) due to novel variant of the inositol 1,4,5-trisphosphate receptor type 1 (ITPR1) gene.@*METHODS@#The child was subjected high-throughput sequencing, and candidate variant was verified by Sanger sequencing of his family members.@*RESULTS@#The child was found to harbor a c.800C>T (p.T267M) variant of the ITPR1 gene, which was not found in his parents and their fetus. The variant has occurred in a hotspot of the ITPR1 gene variants and was unreported before in China. Based on his clinical and genetic characteristics, the child was diagnosed with SCA29.@*CONCLUSION@#The novel heterozygous c.800C>T (p.T267M) of the ITPR1 gene probably underlay the SCA29 in this child.

Analysis of the influential factors for influenza vaccination and their effects among elderly people of Shenzhen Pingshan district / 中国药房

OBJECTIVE To investigate the status and effect of influenza vaccination among some elderly population and their cognition of influenza vaccination in Shenzhen Pingshan district， and to provide reference for improving the vaccination willingness of the elderly population. METHODS Descriptive epidemiological method was used to analyze the status quo of influenza vaccination among some elderly populations in Pingshan district； the Logistic regression model was used to analyze the influential factors of influenza vaccination； the serum antibody levels of the elderly population were analyzed before and after influenza vaccination. RESULTS Totally 140 effective survey question naires were collected from elderly. The elderly who participated in the survey had a better cognition of the main transmission mode of the influenza virus， 122 people answered correctly， and the accuracy was 87.1%. Age， knowledge that influenza vaccine should be given once a year and knowledge of Shenzhen’s free vaccination policy were the promoting factors for influenza vaccination behavior among the elderly. The positive rates of the four influenza antibodies （type A H1， type A H3， type B Victoria， type B Yamagata） after inoculation were higher than before inoculation， with statistical significance. The antibody titer levels after vaccination were generally higher than before. CONCLUSIONS The positive rate of antibody testing and antibody titer in the elderly population after influenza vaccination are higher than before， which effectively protects the health of the elderly population. It is necessary to continuously improve the awareness of the elderly population about influenza vaccination and free vaccination policies.

Free perforator flap of radial collateral artery on reconstruction of first web contracture after hand injury / 中华显微外科杂志

Objective:To summarise the effect of free perforator flap of radial collateral artery on reconstruction of first web contracture after hand injury.Methods:Retrospective analysis was conducted based on the clinical data of patients with first web contracture after hand injury in the Department of Hand and Foot Surgery and Rehabilitation, Guangdong Work Injury Rehabilitation Hospital from November 2019 to June 2022. Ten patients, 8 males and 2 females aged between 27 and 51 years old with an average of 40.5 years old were included. There were 6 left hands and 4 right hands. Width and the included angle of first web were measured before surgery. Four hands were classified as severe first web contracture, and the rest of 6 hands had moderate first web contracture. After release scars of the first web, the areas of wound were 5.5 cm × 2.0 cm - 10.5 cm × 3.0 cm. The flaps sized were 6.0 cm×2.5 cm - 11.0 cm × 3.5 cm. All of flaps carried the posterior cutaneous nerve of forearm. Donor sites were closed directly. All patients were included in postoperative follow-up regularly through outpatient clinic or via WeChat reviews. The colour, texture, process in change of the transferred flaps, donor and recipient sites healing and complications were observed.Results:All 10 flaps survived and the wound healed by first intention. The patients received 7 to 15 months (10.5 months in average) of postoperative follow-up. The flaps were not bulky, texture and colour were satisfactory and without pigmentation. Protective sensations restored in 6 patients. At the last follow-up, average included angle of the first webs was 47.14°±1.68°, in comparison with 35.43°±3.60° before surgery. The average width of first webs was 5.34 cm±0.52 cm, in comparison with 3.17 cm±0.75 cm before surgery, the differences were statistically significant ( P<0.01). Eight hands were rated excellent, and 2 were good. There were only linear scars left at the donor sites, without sign of radial nerve injury. Conclusion:The free perforator flap of radial collateral artery is a safe and effective method for repair of first web contracture after hand injury.