Objective Present study aimed to characterize the alteration of cortical thickness in first-episode, never-medicated, adult patients with major depressive disorder (MDD), and explore whether such deficits were related with their disease duration and clinical symptom severity. Methods Thirty-seven adult MDD patients were recruited from March 2013 to August 2015 as patient group, and 41 healthy volunteers were as control group. All the patients underwent three-dimensional spoiled gradient recalled (3D-SPGR) sequences, and the images were acquired. Constructions of the cortical surface were developed from 3D-SPGR images using FreeSurfer software, and the thickness of the entire cortex was measured according to the automated surface reconstruction, transformation, and high-resolution inter-subject alignment procedures. Finally, cortical thickness was compared between the two groups, and the relativity between clinical symptom severity, disease progression and clinical scores were analyzed using the General Linear Model (GLM). Results Our results revealed a significant increase in cortical thickness(P<0.05, false discovery rate corrected) in the left anterior and middle cingulate cortex, bilateral precentral cortex, left paracentral cortex, bilateral superior parietal cortex, left temporal pole, and right lateral occipital cortex (cortical thickness 1.89-2.87 mm, cortical volume 34-384 mm2, P<0.05) in MDD patients compared to healthy controls, while no reversed alternation was found. In addition, clinical symptom severity and disease progression showed no correlation with the cortical thickness abnormalities in MDD group(P>0.05). Conclusion Excluding the impact of treatment, our study showed that the cortical thickness change was mainly located in the prefrontal-limbic system in the in early course of MDD.

Objective:To investigate the genetic correlation of interleukin-12 (IL-12) pathway-related gene single nucleotide polymorphisms (SNPs) with psoriasis vulgaris and their interaction with HLA-Cw*0602 in populations of Mongolian and Han nationalities in Inner Mongolia.Methods:From December 2012 to March 2018, 1 409 inpatients with psoriasis vulgaris (1 030 of Han nationality and 379 of Mongo-lian nationality) and 1 483 healthy controls (965 of Han nationality and 518 of Mongolian nationality) were collected from the Affiliated Hospital of Inner Mongolia Medical University, and served as patient group and control group respectively. Five milliliters of peripheral venous blood samples were collected from these subjects, and DNA was extracted. Nine SNPs located in the coding regions of IL-12 pathway-related genes were selected, including IL-12B (rs2082412, rs2288831, rs3212227, rs3213094, rs7709212) , IL-23R (rs11209026, rs2201841, rs7530511) and IL-28RA (rs4649203) genes, and detected by next-generation sequencing. HLA-Cw*0602 was genotyped by polymerase chain reaction with sequence-specific primers (PCR-SSP) . Statistical analysis was carried out with PLINK1.07 software, Chi-square test was used to compare allele frequencies between the 2 groups, relative risk estimates of alleles were calculated by using odds ratio ( OR) , and chi-square test for R × C contingency tables was used for haplotype analysis. Results:The allele frequencies of rs2082412, rs2288831, rs3212227, rs3213094 and rs7709212 in the IL-12B gene were significantly lower in the patients with psoriasis vulgaris of Han nationality than in the controls of Han nationality (all P < 0.005) ; the allele frequency of rs3213094 in the IL-12B gene was significantly lower in the patients of Mongolian nationality than in the controls of Mongolian nationality ( P < 0.005) . The prevalence of HLA-Cw*0602 was significantly lower in the patients with psoriasis vulgaris of Han and Mongolian nationalities than in the controls of corresponding nationalities (both P < 0.005) . As stratification analysis showed, the allele frequencies of rs2082412, rs2288831, rs3212227, rs3213094 and rs7709212 in the IL-12B gene were significantly lower in HLA-Cw*0602-positive patients of Han nationality than in HLA-Cw*0602-positive controls of Han nationality (all P < 0.005) , while there was no significant difference between HLA-Cw*0602-negative patients of Han nationality and HLA-Cw*0602-negative controls of Han nationality (all P > 0.05) . Among the HLA-Cw*0602-positive or negative populations of Mongolian nationality, no significant difference was observed in the allele frequencies between the patients and controls (all P > 0.005) . Haplotypes were constructed using 5 SNPs in the IL-12B gene, and there was no significant difference in the frequencies of 6 haplotypes between the patients and controls of Mongolian or Han nationality (all P > 0.005) ; stratification analysis showed that there was no significant difference in the frequencies of 7 haplotypes between HLA-Cw*0602-positive/negative patients and controls of Mongolian or Han nationality (all P > 0.005) . Conclusion:IL-12 pathway-related gene polymorphisms are associated with psoriasis vulgaris in the populations of Mongolian and Han nationalities in Inner Mongolia, and there may be interaction between IL-12B and HLA-Cw*0602 in the occurrence of psoriasis vulgaris.

Objective:To evaluate the role of spinal Rac1 signaling pathway in the maintenance of bone cancer pain (BCP) in rats.Methods:Sixty-four clean-grade adult female Sprague-Dawley rats, aged 8-10 weeks, weighing 180-200 g, were divided into 4 groups using a random number table method: sham operation group (group S, n=8), BCP group ( n=40), BCP plus normal saline group (group BCP+ Veh, n=8), and BCP plus NSC23766 group (group BCP+ NSC, n=8). BCP was induced by injecting Walker 256 mammary gland cancer cell suspension 5 μl (1×10 5 cells/μl) into the bone marrow of the right tibia of rats in BCP, BCP+ Veh and BCP+ NSC groups, while the equal volume of inactivated tumor cells were injected in group S. On 9-11 days after BCP, specific Rac1 inhibitor NSC23766 (5 μg/5 μl) was intrathecally injected once a day in group BCP+ NSC, and the equal volume of normal saline (5 μl) was given once a day in group BCP+ Veh.The mechanical paw withdrawal threshold (MWT) was measured at 1 day before BCP (T 0) and 3, 5, 7, 14 and 21 days after BCP (T 1-5). Eight rats in each group were sacrificed after measurement of MWT at each time point in BCP group or after the last measurement of MWT in S, BCP+ Veh and BCP+ NSC groups, and the lumbar segment (L 4-6) of the spinal cord was removed for determination of the expression of Rac1 signaling pathway-related proteins Rac1, GTP-Rac1, PAK1 and p-PAK1 using Western blot. Results:Compared with group S, MWT was significantly decreased at T 3-5 in BCP, BCP+ Veh and BCP+ NSC groups, and the expression of GTP-Rac1 and p-PAK1 was up-regulated at T 3-5 in group BCP ( P<0.05). Compared with group BCP+ Veh, MWT was significantly increased at T 4, 5, and the expression of GTP-Rac1 and p-PAK1 was down-regulated in group BCP+ NSC ( P<0.05). Conclusion:Spinal Rac1 signaling pathway is involved in the maintenance of BCP in rats.

Objective:To investigate the effect of modified Shenling Baizhu San on the pathological changes and extracellular matrix (ECM) in rats with peritoneal fibrosis induced by peritoneal dialysate fluid (PDF) with different sugar concentration and its mechanism.Methods:Seventy male Sprague-Dawley (SD) rats were randomly divided into control group, different sugar content PDF model groups and corresponding traditional Chinese medicine intervention groups, with 10 rats in each group. Peritoneal fibrosis model was reproduced by intraperitoneal injection of 100 mL·kg -1·d -1 PDF containing 1.5%, 2.5% and 4.25% sugar once a day for 8 weeks. The rats in the control group were given the same amount of normal saline. The rats in the traditional Chinese medicine intervention groups were treated with gavage of 10 mL/kg of modified Shenling Baizhu San (containing 2.014 g crude drug per liter) immediately after modeling. The PDF model groups and the control group were given the same amount of normal saline by gavage. After 8 weeks, the peritoneal ultrafiltration volume of rats in each group was measured. The peritoneal tissues were collected and stained with hematoxylin-eosin (HE), and the structural changes and thickness of the parietal peritoneum were observed under a light microscope. After Masson staining, the deposition of collagen fibers was observed under a light microscope. Western blotting was used to detect the protein expressions of E-cadherin,?α-smooth muscle actin (α-SMA) and Vimentin, the main components of ECM in parietal peritoneum. The positive expressions of matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), and transforming growth factor-β1 (TGF-β1) were detected by immunohistochemical staining. Results:Compared with the control group, PDF with different sugar contents could induce peritoneal fibrosis in rats, and the degree of fibrosis was gradually aggravated with the increase of sugar content, which was manifested as peritoneal thickening, increased collagen fiber deposition, decreased peritoneal ultrafiltration volume, down-regulated expressions of E-cadherin and MMP-9 in peritoneal tissue, and up-regulated expressions of α-SMA, Vimentin, TIMP-1 and TGF-β1, and the pathological changes and ECM accumulation in peritoneal tissues were more serious in 4.25% PDF model group. After the intervention of modified Shenling Baizhu San, compared with the corresponding PDF model groups, the peritoneal fibrosis of rats was improved to varying degrees, and the effect of the 4.25% PDF+traditional Chinese medicine intervention group was more significant, the parietal peritoneum was significantly thinner (μm: 101.86±16.01 vs. 140.65±10.13, P < 0.05), collagen fiber deposition was significantly reduced, peritoneal ultrafiltration volume was significantly increased (mL: -0.01±3.45 vs. -3.53±1.84, P < 0.05), the expressions of E-cadherin and MMP-9 in peritoneal tissues were significantly up-regulated [E-cadherin protein (E-cadherin/β-actin): 0.84±0.08 vs. 0.28±0.05, MMP-9 ( A value): 0.60±0.15 vs. 0.37±0.01, both P < 0.05], and the expressions of α-SMA, Vimentin, TIMP-1 and TGF-β1 were significantly down-regulated [α-SMA protein (α-SMA/β-actin): 0.36±0.08 vs. 1.05±0.09, Vimentin protein (Vimentin/β-actin): 0.53±0.07 vs. 1.19±0.04, TIMP-1 ( A value): 0.49±0.06 vs. 0.87±0.02, TGF-β1 ( A value): 0.67±0.04 vs. 0.89±0.10, all P < 0.05]. Conclusions:The degree of peritoneal fibrosis gradually increased with the increase of PDF sugar content in rats. Modified Shenling Baizhu San can improve peritoneal fibrosis induced by PDF with different sugar contents in rats, and the mechanism is related to the changes in the expression of fibrosis markers and ECM accumulation.

Objective:To assess the efficacy and safety of cinepazide maleate injection in the treatment of patients with acute ischemic stroke.Methods:A multicenter, randomized, double-blind, placebo-controlled phase Ⅳ clinical trial, led by Peking Union Medical College Hospital, was conducted in 65 Hospitals in China. The efficacy of cinepazide maleate injection in patients with acute anterior circulation cerebral infarction with onset time of ≤48 hours, 7≤National Institute of Health stroke scale (NIHSS) score ≤25 was assessed from August 2016 to February 2019, using the proportion of modified Rankin scale (mRS) score≤1 and Barthel index (BI) score≤95 on day 14 as efficacy endpoint. The patients were divided into treatment group who were treated with cinepazide maleate injection and control group who were treated with placebo.Results:A total 937 patients were involved in the final efficacy analysis (466 in treatment group and 471 in control group). The proportion of subjects with mRS score≤1 on day 14 after treatment were higher in the treatment group than that in the control group (102/466(21.89%) vs76/471(16.14%)). Logistic regression analysis showed that patients treated with cinepazide maleate were significantly more likely to have a favorable outcome (mRS score≤1) than patients treated with placebo on day 14 ( OR=0.677, 95% CI 0.484-0.948 , P=0.023), and patients treated with cinepazide maleate were more likely to reach independence in activities of daily living (Barthel Index ≥95) than those treated with placebo on day 14 (125/466(26.82%) vs 91/471(19.32%); OR=0.632, 95% CI0.459-0.869, P=0.005). The rate of adverse events was similar between the treatment and control groups. Conclusion:The 14-day treatment with cinepazide maleate injection could reduce the degree of disability whereas did not increase the risk of adverse events.

Objective:To confirm the efficacy and safety of cinepazide maleate injection in acute ischemic stroke patients with obvious motor function deficit.Methods:This study is a subgroup analysis of multi-center, randomized, double-blind, placebo-controlled phase Ⅳ clinical trial. A total 812 patients of acute ischemic stroke with obvious limb motor deficit [motor function of limbs score in National Institutes of Health Stroke Scale (NIHSS) ≥4] were enrolled in this subgroup analysis. Patients received either cinepazide maleate injection or placebo. The treatment period was 14 days and follow-up was 90 days. The efficacy endpoints included the proportions of patients with a modified Rankin Scale (mRS) score ≤2, mRS score ≤1 and Barthel Index <95 on day 90. Safety was evaluated by recording all adverse events, monitoring vital signs, laboratory parameters and electrocardiogram.Results:A total of 732 patients were involved in the final efficacy analysis (361 in cinepazide maleate group and 371 in control group). The baseline limb motor function score of NIHSS was 5.23±1.43 in the cinepazide maleate group whereas 5.20±1.36 in the control group. Logistic regression analysis showed that following treatment for 90 days, the proportion of patients with a mRS score ≤2 was significantly higher in the cinepazide maleate group than in the control group [56.0% (202/361) vs 44.2% (164/371), OR=0.60, 95% CI 0.44-0.82, P=0.002]. The proportion of patients with a mRS score ≤1 was higher in the cinepazide maleate group than in the control group [43.3% (139/361) vs 35.2% (118/371), OR=0.69, 95% CI 0.50-0.97, P=0.031]. The proportion of patients with a Barthel Index <95 on day 90 was significantly lower in the cinepazide maleate group than in the control group [45.2% (145/361) vs 55.2% (185/371), OR=0.64, 95% CI 0.46-0.88, P=0.007]. During the treatment and follow-up period, the incidence of the most common adverse events in the cinepazide maleate group was 50.4% (199/395). Constipation and abnormal liver function were more common, but there were no statistically significant differences between the two groups. Conclusion:Cinepazide maleate injection is superior to placebo in improving neurological function and activities of daily living, reducing disability, and promoting functional recovery and safe in patients with acute ischemic stroke with obvious limb motor deficit.

Objective:To investigate the blood pressure change in patients with acute ischemic stroke (AIS) and hypertension treated with cinepazide maleate injection.Methods:This was a subgroup analysis of post-marketing clinical confirmation study of cinepazide maleate injection for acute ischemic stroke: a randomized, double-blinded, multicenter, placebo-parallel controlled trial, which conducted in China from August 2016 to February 2019. Eligible patients fulfilled the inclusive criteria of acute anterior circulation ischemic stroke with National Institutes of Health Stroke Scale (NIHSS) scores of 7-25. The primary endpoints were mean blood pressure of AIS patients treated with cinepazide maleate or control, which were assessed during the treatment period (14 days), and the proportion of the patients with normal blood pressure was analyzed after the treatment period. Furthermore, a subgroup analysis was performed to investigate a possible effect of the history of hypertension on outcomes.Results:This analysis included 809 patients with hypertension. There was no significant difference in patients blood pressure and the proportion of patients with normal blood pressure (60.5% vs. 59.0%, P>0.05) between cinepazide maleate group and control group. Conclusion:Administration of cinepazide maleate injection does not affect the management of clinical blood pressure in patients with AIS.

Objective:To investigate the epidemiological characteristics, diagnosis, treat-ment and prognosis of gallbladder cancer in China from 2010 to 2017.Methods:The single disease retrospective registration cohort study was conducted. Based on the concept of the real world study, the clinicopathological data, from multicenter retrospective clinical data database of gallbladder cancer of Chinese Research Group of Gallbladder Cancer (CRGGC), of 6 159 patients with gallbladder cancer who were admitted to 42 hospitals from January 2010 to December 2017 were collected. Observation indicators: (1) case resources; (2) age and sex distribution; (3) diagnosis; (4) surgical treatment and prognosis; (5) multimodality therapy and prognosis. The follow-up data of the 42 hospitals were collected and analyzed by the CRGGC. The main outcome indicator was the overall survival time from date of operation for surgical patients or date of diagnosis for non-surgical patients to the end of outcome event or the last follow-up. Measurement data with normal distribu-tion were represented as Mean±SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M( Q1, Q3) or M(range), and com-parison between groups was conducted using the U test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. Univariate analysis was performed using the Logistic forced regression model, and variables with P<0.1 in the univariate analysis were included for multivariate analysis. Multivariate analysis was performed using the Logistic stepwise regression model. The life table method was used to calculate survival rates and the Kaplan-Meier method was used to draw survival curves. Log-rank test was used for survival analysis. Results:(1) Case resources: of the 42 hospitals, there were 35 class A of tertiary hospitals and 7 class B of tertiary hospitals, 16 hospitals with high admission of gallbladder cancer and 26 hospitals with low admission of gallbladder cancer, respectively. Geographical distribution of the 42 hospitals: there were 9 hospitals in central China, 5 hospitals in northeast China, 22 hospitals in eastern China and 6 hospitals in western China. Geographical distribution of the 6 159 patients: there were 2 154 cases(34.973%) from central China, 705 cases(11.447%) from northeast China, 1 969 cases(31.969%) from eastern China and 1 331 cases(21.611%) from western China. The total average number of cases undergoing diagnosis and treatment in hospitals of the 6 159 patients was 18.3±4.5 per year, in which the average number of cases undergoing diagnosis and treatment in hospitals of 4 974 patients(80.760%) from hospitals with high admission of gallbladder cancer was 38.8±8.9 per year and the average number of cases undergoing diagnosis and treatment in hospitals of 1 185 patients(19.240%) from hospitals with low admission of gallbladder cancer was 5.7±1.9 per year. (2) Age and sex distribution: the age of 6 159 patients diagnosed as gallbladder cancer was 64(56,71) years, in which the age of 2 247 male patients(36.483%) diagnosed as gallbladder cancer was 64(58,71)years and the age of 3 912 female patients(63.517%) diagnosed as gallbladder cancer was 63(55,71)years. The sex ratio of female to male was 1.74:1. Of 6 159 patients, 3 886 cases(63.095%) were diagnosed as gallbladder cancer at 56 to 75 years old. There was a significant difference on age at diagnosis between male and female patients ( Z=-3.99, P<0.001). (3) Diagnosis: of 6 159 patients, 2 503 cases(40.640%) were initially diagnosed as gallbladder cancer and 3 656 cases(59.360%) were initially diagnosed as non-gallbladder cancer. There were 2 110 patients(34.259%) not undergoing surgical treatment, of which 200 cases(9.479%) were initially diagnosed as gallbladder cancer and 1 910 cases(90.521%) were initially diagnosed as non-gallbladder cancer. There were 4 049 patients(65.741%) undergoing surgical treatment, of which 2 303 cases(56.878%) were initially diagnosed as gallbladder cancer and 1 746 cases(43.122%) were initial diagnosed as non-gallbladder cancer. Of the 1 746 patients who were initially diagnosed as non-gallbladder cancer, there were 774 cases(19.116%) diagnosed as gallbladder cancer during operation and 972 cases(24.006%) diagnosed as gallbladder cancer after operation. Of 6 159 patients, there were 2 521 cases(40.932%), 2 335 cases(37.912%) and 1 114 cases(18.087%) undergoing ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) examination before initial diagnosis, respec-tively, and there were 3 259 cases(52.914%), 3 172 cases(51.502%) and 4 016 cases(65.205%) undergoing serum carcinoembryonic antigen, CA19-9 or CA125 examination before initially diagnosis, respectively. One patient may underwent multiple examinations. Results of univariate analysis showed that geographical distribution of hospitals (eastern China or western China), age ≥72 years, gallbladder cancer annual admission of hospitals, whether undergoing ultrasound, CT, MRI, serum carcinoembryonic antigen, CA19-9 or CA125 examination before initially diagnosis were related factors influencing initial diagnosis of gallbladder cancer patients ( odds ratio=1.45, 1.98, 0.69, 0.68, 2.43, 0.41, 1.63, 0.41, 0.39, 0.42, 95% confidence interval as 1.21-1.74, 1.64-2.40, 0.59-0.80, 0.60-0.78, 2.19-2.70, 0.37-0.45, 1.43-1.86, 0.37-0.45, 0.35-0.43, 0.38-0.47, P<0.05). Results of multivariate analysis showed that geographical distribution of hospitals (eastern China or western China), sex, age ≥72 years, gallbladder cancer annual admission of hospitals and cases undergoing ultrasound, CT, serum CA19-9 examination before initially diagnosis were indepen-dent influencing factors influencing initial diagnosis of gallbladder cancer patients ( odds ratio=1.36, 1.42, 0.89, 0.67, 1.85, 1.56, 1.57, 0.39, 95% confidence interval as 1.13-1.64, 1.16-1.73, 0.79-0.99, 0.57-0.78, 1.60-2.14, 1.38-1.77, 1.38-1.79, 0.35-0.43, P<0.05). (4) Surgical treatment and prognosis. Of the 4 049 patients undergoing surgical treatment, there were 2 447 cases(60.435%) with complete pathological staging data and follow-up data. Cases with pathological staging as stage 0, stage Ⅰ, stage Ⅱ, stage Ⅲa, stage Ⅲb, stage Ⅳa and stage Ⅳb were 85(3.474%), 201(8.214%), 71(2.902%), 890(36.371%), 382(15.611%), 33(1.348%) and 785(32.080%), respectively. The median follow-up time and median postoperative overall survival time of the 2 447 cases were 55.75 months (95% confidence interval as 52.78-58.35) and 23.46 months (95% confidence interval as 21.23-25.71), respectively. There was a significant difference in the overall survival between cases with pathological staging as stage 0, stage Ⅰ, stage Ⅱ, stage Ⅲa, stage Ⅲb, stage Ⅳa and stage Ⅳb ( χ2=512.47, P<0.001). Of the 4 049 patients undergoing surgical treatment, there were 2 988 cases(73.796%) with resectable tumor, 177 cases(4.371%) with unresectable tumor and 884 cases(21.833%) with tumor unassessable for resectabi-lity. Of the 2 988 cases with resectable tumor, there were 2 036 cases(68.139%) undergoing radical resection, 504 cases(16.867%) undergoing non-radical resection and 448 cases(14.994%) with operation unassessable for curative effect. Of the 2 447 cases with complete pathological staging data and follow-up data who underwent surgical treatment, there were 53 cases(2.166%) with unresectable tumor, 300 cases(12.260%) with resectable tumor and receiving non-radical resection, 1 441 cases(58.888%) with resectable tumor and receiving radical resection, 653 cases(26.686%) with resectable tumor and receiving operation unassessable for curative effect. There were 733 cases not undergoing surgical treatment with complete pathological staging data and follow-up data. There was a significant difference in the overall survival between cases not undergoing surgical treatment, cases undergoing surgical treatment for unresectable tumor, cases undergoing non-radical resection for resectable tumor and cases undergoing radical resection for resectable tumor ( χ2=121.04, P<0.001). (5) Multimodality therapy and prognosis: of 6 159 patients, there were 541 cases(8.784%) under-going postoperative adjuvant chemotherapy and advanced chemotherapy, 76 cases(1.234%) under-going radiotherapy. There were 1 170 advanced gallbladder cancer (pathological staging ≥stage Ⅲa) patients undergoing radical resection, including 126 cases(10.769%) with post-operative adjuvant chemotherapy and 1 044 cases(89.231%) without postoperative adjuvant chemo-therapy. There was no significant difference in the overall survival between cases with post-operative adjuvant chemotherapy and cases without postoperative adjuvant chemotherapy ( χ2=0.23, P=0.629). There were 658 patients with pathological staging as stage Ⅲa who underwent radical resection, including 66 cases(10.030%) with postoperative adjuvant chemotherapy and 592 cases(89.970%) without postoperative adjuvant chemotherapy. There was no significant difference in the overall survival between cases with postoperative adjuvant chemotherapy and cases without postoperative adjuvant chemotherapy ( χ2=0.05, P=0.817). There were 512 patients with pathological staging ≥stage Ⅲb who underwent radical resection, including 60 cases(11.719%) with postoperative adjuvant chemotherapy and 452 cases(88.281%) without postoperative adjuvant chemotherapy. There was no significant difference in the overall survival between cases with postoperative adjuvant chemo-therapy and cases without post-operative adjuvant chemo-therapy ( χ2=1.50, P=0.220). Conclusions:There are more women than men with gallbladder cancer in China and more than half of patients are diagnosed at the age of 56 to 75 years. Cases undergoing ultrasound, CT, serum CA19-9 examination before initial diagnosis are independent influencing factors influencing initial diagnosis of gallbladder cancer patients. Preoperative resectability evaluation can improve the therapy strategy and patient prognosis. Adjuvant chemotherapy for gallbladder cancer is not standardized and in low proportion in China.