Real-world tobacco cessation practice in China: findings from the prospective, nationwide multicenter China National Tobacco Cessation Cohort Study (CNTCCS).

Background: Tobacco cessation is proven to be the most effective and cost-effective strategy for smokers to reduce their risk of smoking-related disease and premature death. Providing effective, efficient, safe, and patient-centred tobacco cessation treatment to reach those who need them is a significant challenge. To date, only a few nationwide studies in China have assessed the overall clinical care practice and treatment outcome of tobacco cessation. Methods: This a prospective, nationwide, multicenter, cohort study covering all Eastern China, Northwest China, Central China, North China, Southwest China, Northeast China, and South China. Participants who were current smokers aged 18-85 years attending clinic for smoking cessation were included. All the participants were treated with 3-month cessation treatment and followed up for 3 months. Data were collected prospectively using online system. The primary outcome was 7-day point abstinence rate at 24 weeks, validated biochemically by an expired carbon monoxide level of less than 10 ppm. The participants lost to follow-up or not providing validation were included as non-abstainers. Findings: A representative sample of 3557 participants were recruited and 2943 participants were included into this analysis. These participants had mean age of 53.05 years, and 94.8% were males, with 75.8% showing symptoms of tobacco dependence. A total of 965 (32.8%) participants were treated with Bupropion + behavioural counselling, followed by 935 (31.8%) with behavioural counselling, 778 (26.4%) with Varenicline + behavioural counselling, 135 (4.6%) with alternative treatments + behavioural counselling, and 130 (4.4%) with nicotine replacement therapy (NRT) + behavioural counselling. After 3-month treatment and 3-month follow-up, 21.74% of the participants quit smoking at 24 weeks. In the multivariable-adjusted analyses, quitting smoking was significantly associated with female, higher socioeconomic status, poor health condition, different treatment received, and less smoking intensity. The tobacco cessation treatment varied widely across different areas of China. In particular, the areas with higher usage of cessation medication were associated with better cessation treatment outcome. Interpretation: The CNTCCS is the first large-scale nationwide cohort study of smoking cessation in China. Rich data collected from this prospective cohort study provided the opportunity to evaluate the clinical practice of tobacco cessation treatment in China. Funding: Chinese Academy of Medical Sciences (CAMS) Initiative for Innovative Medicine (CAMS 2021-I2M-1-010), Heilongjiang Provincial Science and Technology Key Program (2022ZXJ03C02), and National Key R&D Program of China (grant no. 2017YFC1309400).

Acid and alkali-resistant fabric-based triboelectric nanogenerator for self-powered intelligent monitoring of protective clothing in highly corrosive environments.

The corrosion of materials severely limits the application scenarios of triboelectric nanogenerators (TENGs), especially in laboratories, chemical plants and other fields where leakage of chemically corrosive solutions is common. Here, we demonstrate a chemical-resistant triboelectric nanogenerator (CR-TENG) based on polysulfonamide (PSA) and polytetrafluoroethylene (PTFE) non-woven fabrics. The CR-TENG can stably harvest biological motion energy and perform intelligent safety protection monitoring in a strong corrosive environment. After treatment with strong acid and alkali solution for 7 days, the fabric morphology, diameter, tensile properties and output of CR-TENG are not affected, showing high reliability. CR-TENG integrated into protective equipment can detect the working status of protective equipment in real time, monitor whether it is damaged, and provide protection for wearers working in high-risk situations. In addition, the nonwoven-based CR-TENG has better wearing comfort and is promising for self-powered sensing in harsh environments.

Origin of Rebound Suppression for Dilute Polymer Solution Droplets on Superhydrophobic Substrate.

Controlling droplet deposition with a minute amount of polymer additives is of profound practical importance in a wild range of applications. Previous work ascribed the relevant mechanisms to extensional viscosity, normal stress, wetting properties, etc., but the mechanism remains controversial. In this paper, we employ molecular dynamics simulations systematically for the first time to investigate the origin of rebound suppression for dilute polymer solution droplets on a flat superhydrophobic substrate. The results demonstrate that polymer-substrate interactions and impact velocities dominate the antirebound phenomenon. For low impact velocities, the dynamic characteristics of droplets are insensitive to polymer additives. However, large impact velocities will enhance the stretch behavior of polymer chains and make the chains closer to the substrate, increasing the probability of polymer molecules contacting the bottom substrate. With the cooperation of strong polymer-substrate interactions, polymer molecules can be absorbed easily by the bottom substrate, resisting the retraction process and leading to the onset of the antirebound behavior.

The piecewise parabolic method for elastic-plastic flow in solids.

A numerical technique of high-order piecewise parabolic method in combination of HLLD ("D" denotes Discontinuities) Riemann solver is developed for the numerical simulation of elastic-plastic flow. The introduction of the plastic effect is realized by decomposing the total deformation gradient tensor as the product of elastic and plastic deformation gradient tensors and adding plastic source term to the conservation law model equation with the variable of the elastic deformation gradient tensor. For the solution of the resulting inhomogeneous equation system, a temporal splitting strategy is adopted and a semi-implicit scheme is performed to solve the ODES in the plastic step, which is conducted to account for the contributions from plastic source terms. As seen from the results of test cases involving large deformation and high strain rate, the computational model used can reflect the characteristics of constitutive relation of material under strong impact action and our numerical method can realize the exact simulation of the elastic-plastic behavior of solid material, especially the accurate capture of the elastic-plastic waves. Further, it could also deal with high-speed impact problems with multi-material components, catching material interfaces correctly and keeping the interfaces sharp, when combined with interface tracking technique such as the level-set algorithm.

The piecewise parabolic method for Riemann problems in nonlinear elasticity.

We present the application of Harten-Lax-van Leer (HLL)-type solvers on Riemann problems in nonlinear elasticity which undergoes high-load conditions. In particular, the HLLD ("D" denotes Discontinuities) Riemann solver is proved to have better robustness and efficiency for resolving complex nonlinear wave structures compared with the HLL and HLLC ("C" denotes Contact) solvers, especially in the shock-tube problem including more than five waves. Also, Godunov finite volume scheme is extended to higher order of accuracy by means of piecewise parabolic method (PPM), which could be used with HLL-type solvers and employed to construct the fluxes. Moreover, in the case of multi material components, level set algorithm is applied to track the interface between different materials, while the interaction of interfaces is realized through HLLD Riemann solver combined with modified ghost method. As seen from the results of both the solid/solid "stick" problem with the same material at the two sides of contact interface and the solid/solid "slip" problem with different materials at the two sides, this scheme composed of HLLD solver, PPM and level set algorithm can capture the material interface effectively and suppress spurious oscillations therein significantly.

Stability analysis of Rayleigh-Bénard convection in a cylinder with internal heat generation.

The flow instabilities of Rayleigh-Bénard convection in a cylinder with effect of uniform internal heat source are investigated numerically. The instabilities of the static state and of axisymmetric flows are investigated by linear stability analysis. The convection threshold depends on the strength of internal heat source q and the aspect ratio of the cylinder Γ. The stability of axisymmetric flows is strongly affected by these two parameters, as well as the Prandtl number Pr. Depending on the value of q, three regimes are identified: weak internal heating, moderate internal heating, and strong internal heating regime. In a weak internal heating regime, the instability characteristics are similar to Rayleigh-Bénard convection. In a moderate internal heating regime, intense interaction of buoyancy instability and hydrodynamic instability result in complex instability curves. When q is large enough, the internal heating effect overwhelms the boundary heating effect. Specifically, the influence of Pr on instability is studied at a moderate internal heat strength q=6.4. An extremely multivalued stability curve is observed. At most five critical Rayleigh numbers can be determined for the axisymmetry-breaking instability at a certain Prandtl number. An axisymmetric unsteady instability mode is observed as well. By nonlinear simulation, the oscillatory flow patterns are obtained, and the axisymmetry-breaking bifurcation of the unsteady toroidal flow is studied.

Rayleigh-Bénard convection in a vertical annular container near the convection threshold.

The instabilities and transitions of flow in an annular container with a heated bottom, a cooled top, and insulated sidewalls are studied numerically. The instabilities of the static diffusive state and of axisymmetric flows are investigated by linear stability analysis. The onset of convection is independent of the Prandtl number but determined by the geometry of the annulus, i.e., the aspect ratio Γ (outer radius to height) and radius ratio δ (inner radius to outer radius). The stability curves for onset of convection are presented for 0.001≤δ≤0.8 at six fixed aspect ratios: Γ=1, 1.2, 1.6, 1.75, 2.5, and 3.2. The instability of convective flow (secondary instability), which depends on both the annular geometry and the Prandtl number, is studied for axisymmetric convection. Two pairs of geometric control parameters are chosen to perform the secondary instability analysis-Γ=1.2, δ=0.08 and Γ=1.6, δ=0.2-and the Prandtl number ranges from 0.02 to 6.7. The secondary instability exhibits some similarities to that for convection in a cylinder. A hysteresis stability loop is found for Γ=1.2, δ=0.08 and frequent changes of critical mode with Prandtl number are found for Γ=1.6, δ=0.2. The three-dimensional flows beyond the axisymmetry-breaking bifurcations are obtained by direct numerical simulation for Γ=1.2, δ=0.08.

Expression and functional characterization of a recombinant targeted toxin with an uPA cleavable linker in Pichia pastoris.

A recombinant targeted toxin (Disintegrin-Conj-Mel) was developed that contained a disintegrin connected to cytotoxic melittin by a urokinase plasminogen activator (uPA)-cleavable linker. This recombinant targeted toxin was designed to target tumor cells expressing integrin αvß3. The fusion gene was expressed under the control of the promoter AOX1 in Pichia pastoris. Electrophoresis by SDS-PAGE and Western blotting assays of culture broth from a methanol-induced expression strain, demonstrated that an approximately 13 kDa fusion protein was secreted into the culture medium. The molecular weight was that calculated from the predicted amino acid sequence. After optimizing the growth and expression conditions of the transformant strain, about 160 mg/L of the recombinant protein was achieved. The recombinant protein was purified to more than 95% purity by SP Sepharose ion exchange chromatography and Sephadex G-75 gel filtration chromatography. The hemolysis bioactivity test revealed that the fusion had no hemolytic activity or cytotoxicity against uPA non-expressing 293 cells, but exerted dose-dependent inhibition on uPA-expressing A549 cell proliferation.

[Influence of excessive complement activation on pathological process of acute graft versus host disease in mice].

This study was aimed to explore the influence of excessive complement activation on the pathological process of acute graft-versus-host disease (aGVHD) in mice. A murine model with aGVHD was established by injecting cell mixture containing splenocytes and bone marrow cells at 2:1 ratio from donor C57BL/6(H-2K(b)) mice into recipient BALB/c (H-2K(d)) mice within 4-6 hours after 8 Gy (60)Co γ-ray total body irradiation. The mice received syngeneic bone marrow transplantation were used as control group. After transplantation, the mice were monitored daily for body weight and mortality. At day 14, all mice were sacrificed and each liver was freshly dissociated for histological analysis. The hepatic mRNA abundance for complement components C3a and C5a as well as receptors for these two anaphylatoxin were tested by real-time quantitative PCR method. And the levels of C3a and C5a production in liver were detected by ELISA. The deposition of complement C3 in liver was determined by immunofluorescence staining using frozen section. The results indicated that as compared with syngeneic bone-marrow transplantation control group, experimental animals underwent aGVHD characterized by weight loss, depilation, diarrhea and lassitude. Interestingly, the hepatic mRNA expression for complement anaphylatoxin family member C3a and C5a as well as their receptors C3aR and C5aR1 in mice with aGVHD were significantly up-regulated in comparison with control group (p < 0.05). Consistently, the content of C3a and C5a in liver increased markedly in mice with aGVHD (p < 0.01). For animals ongoing aGVHD, complement component C3 depositions were observed in hepatic portal areas, around which massive inflammatory cell infiltration was also observed. It is concluded that in aGVHD animals, excessive complement activation occurs, and the activated complement components participate in pathological process of the aGVHD.

[Attitudes and actions of chronic obstructive pulmonary disease patients on treatment:a national multi-center investigative study].

OBJECTIVE: To investigate the attitudes and actions of patients with chronic obstructive pulmonary disease (COPD) on treatment. METHODS: A nation-wide multi-center, questionnaire study was carried out to investigate the patient understanding and experience of COPD treatment between Sep. 2007 and Dec. 2008. The questionnaire included the patients' understanding of goal of COPD treatment, previous treatment, and expectation on drugs. The data were analyzed by descriptive statistical methods. RESULTS: 2072 patients with COPD in 11 centers were interviewed in the study. The final effective questionnaires were collected from 1698 cases. 653 patients had known of COPD. The attitudes and actions on treatment were analyzed based on these patients. The patients had different understanding of goals for COPD treatment, including 59.1% (384/650) for relieving symptoms. In recent 3 months, the most commonly used drugs were theophylline (53.7%, 351/653), iprotropium (39.8%, 260/653), tiotropium (27.1%, 177/653). 72.0% (465/646) patients used the drugs according to the prescriptions. There were more than 80% patients who did not understand the side effects of anti-cholinergics, ß-adrenergic agonists, inhaled steroids, inhaled steroid/long-acting ß-agonist combination therapy, or theophyllines. 37.4% (240/641) patients were afraid of side effects of inhaled steroids. 42.2% (274/650) patients often took antibiotics. There was no oxygen supply at home in 60.1% (391/651) patients. 70.5% (457/648) did not have pulmonary rehabilitation. Requirement of long-term regular treatment was considered in 77.4% (500/646) patients. The most important thing about patients' attitude on ideal drugs for COPD was drug efficacy (79.6%, 481/604). The most ideal drug used in the past was fluticasone/salmeterol or tiotropium (16.9%, 78/461). CONCLUSIONS: Patients had different attitudes and actions on COPD treatment. Patient education should be strengthened to realize treatment goals for COPD.

CD3 mAb treatment ameliorated the severity of the cGVHD-induced lupus nephritis in mice by up-regulation of Foxp3+ regulatory T cells in the target tissue: kidney.

Teff/Treg imbalance orchestrated the onset and the progression of the lupus nephritis in a DBA/2→B6D2F1 murine model with cGVHD. In this paper, we first used 145-2C11 Ab to treat these human SLE-like diseased animals. The results showed that short-term low-dose anti-CD3 antibody treatment induced a significant remission of established proteinuria, production of autoantibodies, immune complex deposition and renal parenchyma lesions in lupus nephritic mice. Of note, we found a robust up-regulation of Foxp3 mRNA expression in the target tissue: kidney from mice with anti-CD3 antibody treatment compared to those with control IgG treatment. Likewise, an increased renal mRNA abundance for IL-10 was also observed in anti-CD3 antibody treated mice. In contrast, genes associated with inflammation and fibrosis as well as cytokines related to effector T cell responses were down-regulated by anti-CD3 mAb treatment. These findings suggested that short-term low-dose anti-CD3 antibody treatment might induced an IL-10-secreting Foxp3(+) regulatory T cells in this cGVHD target tissue: kidney, that suppressed the activation of effector T cells (Th1, Th2 and Th17), thus ameliorating the severity of the lupus nephritis in mice.

[Plastic bronchitis associated with severe influenza A (H1N1) in children: a case report and review of the literature].

OBJECTIVE: to improve understanding of the pathological and clinical features, diagnosis and treatment of plastic bronchitis associate with influenza A (H1N1). METHODS: one case of plastic bronchitis associated with influenza A (H1N1) diagnosed and treated in our hospital in January 2010 was reported and 19 cases of plastic bronchitis reported in the literature were reviewed. RESULTS: we describe a 5-year-old Chinese Japanese boy presenting with cough for 2 days, gasping and fever for 1 day was admitted. Left lung atelectasis and pneumothorax were found on chest X-ray examination. Pathologically, plastic bronchitis was diagnosed after the endogenous foreign body was extracted by bronchoscopy and classified as type 1 cast. In addition, influenza A (H1N1) was confirmed by the swabs which showed positive for H1N1 nucleic acid. The condition was controlled and the patient was cured and discharged after 16-days' treatment with antiviral therapy, low-dose corticosteroids, and antibiotics. CONCLUSION: plastic bronchitis associated with influenza A (H1N1) is a rare life-threatening disorder. The diagnosis could be made based on pathological findings of the bronchial casts as well as the positive H1N1 nucleic acid detection. Bronchoscopic extraction of casts in plastic bronchitis is not only useful for early diagnosis but an effective therapeutic modality for the disease. Influenza A (H1N1) may be a cause of plastic bronchitis.

[The expression and implications of human alpha-defensin 1-3 in serum and induced sputum in patients with chronic obstructive pulmonary disease].

OBJECTIVE: To measure the levels of human alpha-defensin 1-3 (HNP1-3) in the serum and induced sputum in patients with chronic obstructive pulmonary disease (COPD) and therefore to investigate the possible roles of HNP1-3 in COPD. METHODS: Thirty patients with acute exacerbation of COPD, 21 patients with stable COPD, and 22 healthy subjects were recruited. The concentrations of HNP1-3 and interleukin-8 (IL-8) in serum and induced sputum were measured by enzyme-linked immunosorbent assay (ELISA). The correlations among HNP1-3, neutrophils, IL-8, and lung functions were investigated. The data were analyzed using a statistical software package (SPSS 11.5). Variables were compared with One-Way ANOVA or Chi-square test. The correlations between variables were analyzed using Pearson's correlation coefficient or Spearman correlation coefficient. RESULTS: The sputum HNP1-3 level was significantly higher in AECOPD patients [9,652(4,272 -12,576) ng/L] than in healthy subjects [4,194 (700 -10,505) ng/L, chi2 =7.53, P <0.01] and in stable COPD patients [7,011(6,658 -7,319) ng/L, chi2 = 10.24, P <0.01]. There was significant difference among the three groups (chi2 =7.31, P <0.05). There was no significant difference in the serum HNP1-3 level among the three groups: AECOPD group [51(39 - 173) ng/L], stable COPD group [135(113 - 241) ng/L], healthy subjects group [130(13 - 160) ng/ L], chi2 = 5.75, P > 0.05. The sputum HNP1-3 level was positively correlated with the number, percentage of sputum neutrophils, and sputum IL-8 level (r = 0.29 to 0.53, respectively P <0.01). The sputum HNP1-3 level was negatively correlated with FEV1/predicted values, FEV1/FVC, and PaO2 (r= -0.33 to -0.44, respectively P <0.01). CONCLUSIONS: HNP1-3 may be involved in the pathogenesis of airway inflammation in COPD. Sputum HNP1-3 may be a noninvasive marker of severity of COPD.

Endothelin-3 growth factor levels decreased in cervical cancer compared with normal cervical epithelial cells.

We used cDNA microarray analysis of RNA extracted from normal, dysplastic, and cancerous cervical tissues to identify the changes in gene expression during the procession from normal to cancerous cervical epithelial cells. We found the expression of 5 genes in cancerous cervical epithelial cells that were not found in normal cervical epithelial cells, among which were lymphoid-restricted membrane protein, protease serine 2, WD repeat domain 59, thyrotropin-releasing hormone degrading enzyme, and the endothelin-3 growth factor. We then analyzed the expression levels of endothelin growth factors 1, 2, and 3 (ET-1, ET-2, and ET-3) and their receptors A and B (ETR-A and ETR-B) by reverse transcriptase-polymerase chain reaction in 3 cervical cancer cell lines and by immunohistochemical staining in cervical normal, dysplastic, and cancer tissues. ET-1, ET-2, and ET-3 growth factor levels were detectable in the maturing layer of cervical epithelium but not in the germinal layer. All 3 growth factors (ET-1, ET-2, and ET-3) were detected in the cytoplasm of the maturing normal cervical epithelial cells. In addition, there were decreased levels of ET-3 and increased levels of ET-1, ET-2, ETR-A, and ETR-B in cancerous cervical epithelial cells compared with normal cervical epithelial cells. These results suggest that the reduction of ET-3 growth factor levels may be important in the transition from normal to cancerous cervical epithelium.

Multiplicity of steady states in cylindrical Rayleigh-Bénard convection.

Three-dimensional steady Rayleigh-Bénard convection in a vertical cylinder is investigated by numerical simulation and bifurcation analysis. The complex pattern formation beyond the onset of the convection is presented by a bifurcation diagram. The coexistence of multiple stable states is observed near the threshold of the first bifurcation and two group symmetries are summarized for the corresponding primary branches. The first stable target pattern originates through a subcritical bifurcation. A multiplicity of flow states for the Rayleigh number of 14200 is validated numerically in comparison with the experiment, and a four-spoke pattern is observed.

[The expression and significance of urotensin II, nitric oxide, and C-type natriuretic peptide in hypoxia-induced pulmonary hypertension in rats].

OBJECTIVE: To investigate the alteration of plasma and lung tissue homogenate urotensin II (U-II), nitric oxide (NO) and C-type natriuretic peptide (CNP) levels in rats with hypoxia-induced pulmonary hypertension (HPH) and to study the role of these factors and oxygen treatment in the development of HPH. METHODS: Thirty male Wistar rats were randomly divided into three groups: a control group, a group with hypoxia for 14 days and a group with oxygen treatment after hypoxia for 14 days, 10 rats per group. Mean pulmonary arterial pressure (mPAP), mean systematic arterial pressure (mSAP) and right ventriculo hypertrophy index (RVHI) were measured. The plasma levels of U-II, NO, CNP, and the lung tissue homogenate levels of U-II and CNP were measured. The structure of the pulmonary arteries was examined using optical microscope. The microstructure and ultrastructure changes in pulmonary small arteries were examined using electron microscope. RESULTS: The mPAP and RVHI in the hypoxia group [(34.1 +/- 2.8) mm Hg, 0.43 +/- 0.11] were higher than those in the control group [(18.9 +/- 2.0) mm Hg, 0.28 +/- 0.04, all P < 0.01]. The plasma levels of U-II, NO, and CNP [(4.4 +/- 0.9) pg/ml, (20.8 +/- 7.0) micromol/L, (6.6 +/- 1.2) pg/ml], and the lung tissue homogenate levels of U-II and CNP [(6.3 +/- 0.5), (1.89 +/- 0.43) pg/ml] in the hypoxia group were higher than those in the control group [(0.9 +/- 0.4) pg/ml, (13.2 +/- 2.0) micromol/L, (4.0 +/- 0.6) pg/ml, (2.6 +/- 0.5) pg/ml, (0.69 +/- 0.21) pg/ml, respectively, all P < 0.01]. Compared with the hypoxia group, the mPAP, the plasma levels of U-II, NO, and CNP, and the lung tissue homogenate levels of U-II and CNP in the oxygen treatment group [(31.4 +/- 2.0) mm Hg, (2.1 +/- 0.7) pg/ml, (14.8 +/- 1.7) micromol/L, (4.4 +/- 0.7) pg/ml; (3.5 +/- 0.8) pg/ml, (0.74 +/- 0.17) pg/ml, respectively] were significantly decreased (all P < 0.01). The pulmonary vessel morphology changes of the oxygen treatment group were ameliorated. CONCLUSIONS: U-II, NO and CNP are involved in the pathophysiologic process of HPH. Imbalance of these factors may be partially responsible for the development of the disease.

Molecular cloning and sequence analysis of ussurin, a new metalloproteinases/disintegrin from Gloydius ussuriensis.

The metalloproteinases/disintegrins in the snake venom act as platelet aggregation inhibitor by an antagonism against integrin on platelet through its RGD sequence and may play other important role in cell-cell fusion, cell matrix interaction and other cellular function. Ussurin is a new metalloproteinase/disintegrin that was cloned from Gloydius ussuriensis. Poly (A+) RNA was purified from the total RNA preparation from venom gland of a single G. ussuriensis using the poly (A+) tract-mRNA isolation system. A cDNA library was constructed with the SMART PCR cDNA library construction kit. The cDNA library was screened and the positive clones were selected. The full-length cDNA of Ussurin was obtained. The cDNA encoding the Ussurin precursor has a 51bp 5'-UTR, the open reading frame of Ussurin and a 490 bp 3'-UTR, the open reading frame of Ussurin cDNA nucleotide sequence is 1434 bp and codes for 478 amino acids with a predicted molecular mass of 53.2 kD and an isoelectric point of 5.37. There is no potential N-glycosylation site in the deduced sequence region. Its deduced amino acid sequence consists of four region, a signal sequence of 18 amino acid residues, a zymogen pro-peptide of 171 amino acid residues with a cysteine switch motif (PK-MCGVT) in it, a central metalloproteinase domain of 201 amino acid residues containing a conserved zinc-chelating sequence (HEXXHXXGXXH) and a methionine-turn CIM involving zinc banding also, a space sequence between metalloproteinase domain and disintegrin domain of 15 amino acid residues with a conserved T392, T397, S400, which is specific residues of the P-II snake venom metalloproteinases, a disintegrin domain of 73 amino acid residues with a characteristic RGD region and six-disulfide bonds. Ussurin belongs to P-II class. The cDNA sequence and deduced amino acid sequence of Ussurin precursor were compared with homologous sequence in the GenBank database, the result reveals high degree of homology in sequence and organization pattern of domain with metalloproteinase/disintegrin gene family of other snake species. Compared with the alignment of amino acid sequence of metalloproteinase/disintegrin member, hypervariable regions of this member were revealed, besides they share higher homologous in the zymogen domain. It suggests that the hypervariable regions are the counterparts directly suitable for interacting with different domain of receptors, different receptors or substrates.