Characteristics of the Blockage from Air Nozzle Guide Duct in Circulating the Fluidized-Bed Coal Gasifier and Its Formation Mechanism.

Blockage is often generated in the air nozzle guide duct in a circulating fluidized-bed coal gasifier (CFBG), especially with Zhundong sub-bituminous coal (ZSBC) as the raw material. A typical example is found in one CFBG sample from Xinjiang Yihua Chemical Industry Co, Ltd. The serious blockage can be observed obviously. As so far, it is not clear for the characteristics and generation mechanism of the blockage. For analysis, the blockage can be classified into two parts, wall-layer blockage (WLB) and center-layer blockage (CLB). To inhibit its formation, it is of significance to analyze the composition, surface morphology, and formation mechanism of the two blockages. In our experiments, WLB and CLB were tested by XRF, XRD, FTIR, SEM-EDS, and SEM-mapping methods. Results showed that WLB presents high content of Fe, Cr, and Ni, and Fe mainly existed in the form of metal oxides. CLB is dominated by Si (43.04%), derived from silica and alkali and alkaline-earth metals silicates, and the migration of Fe, Cr, and Ni elements from the duct material was observed. Compared with WLB, from FTIR analysis, CLB contains more inorganic minerals, and the absorption peak of inorganic minerals is mainly attributed to asymmetric Si-O-Si. Many fine particles are attached to the surface of the WLB, while the surface of the CLB is smooth, and there is noticeable raised texture, which is presumed to be the result of particle melting and agglomerating as the bottom ash enters the duct in the gasification process. For the formation of the blockage, this paper speculates that it is mainly due to the difference in flow resistance near the air nozzle outlet, resulting in the formation of a flow dead zone at the bottom of the gasifier, which leads to large amounts of ash overcoming the outlet resistance and leaking into the air nozzle, and next, the ash corrodes in the tube, resulting in wall deposition and ultimately blocking the air guide duct. Two methods can be tried to avoid or inhibit the formation of blockage in the duct, including optimizing air nozzle with more wear-resistant and heat-resistant materials and adjusting the distance between air nozzles to avoid mutual interference from ash particles.

NUCKS1 promotes the progression of colorectal cancer via activating PI3K/AKT/mTOR signaling pathway.

Nuclear ubiquitous casein and cyclin-dependent kinase substrate 1 (NUCKS1) is highly expressed in a variety of malignant tumors and functions as an oncogene; however, its role in colorectal cancer (CRC) remains unclear. We aimed to explore the function and regulatory mechanisms of NUCKS1 and potential therapeutic agents targeting NUCKS1 in CRC. We knocked down and overexpressed NUCKS1 in CRC cells and explored its effects in vitro and in vivo. Flow cytometry, CCK-8, Western blotting, colony formation, immunohistochemistry, in vivo tumorigenic, and transmission electron microscopy analyses were performed to determine the effects of NUCKS1 on CRC cell function. LY294002 was used to examine the mechanism of NUCKS1 expression in CRC cells. Potential therapeutic agents for NUCKS1-high CRC patients were analyzed using the CTRP and PRISM datasets, and the function of selected agents was determined by CCK-8 and Western blotting. We revealed that NUCKS1 was highly expressed in CRC tissues and clinically correlated with poor prognosis in CRC patients. NUCKS1 knockdown induces cell cycle arrest, inhibits CRC cell proliferation, and promotes apoptosis and autophagy. These results were reversed when NUCKS1 was overexpressed. Mechanistically, NUCKS1 exerts a cancer-promoting function by activating the PI3K/AKT/mTOR signaling pathway. This was reversed when LY294002 was used to inhibit the PI3K/AKT pathway. Furthermore, we determined that mitoxantrone exhibited high drug sensitivity in NUCKS1-overexpressing CRC cells. This work demonstrated NUCKS1 plays a crucial role in CRC progression via the PI3K/AKT/mTOR signaling pathway. Additionally, mitoxantrone may be a potential therapeutic agent for CRC treatment. Therefore, NUCKS1 represents a promising anti-tumor therapeutic target.

Case report: A relatively rare adverse event caused by carbetocin- placenta interception.

Placenta interception is extremely rare, and herein, we report the case of a 33-year-old woman with placenta interception during cesarean section caused by carbetocin, which was intravenously injected immediately after delivery of the infant to prevent postpartum hemorrhage. There was no sign of placental separation in the third stage of labor. A protuberance with gross subserous blood vessels in the left fundus of the uterus was detected and was misdiagnosed as placental accreta. The patient was transferred to the district referral hospital to manage the protuberance after stitching up the incision. On opening the original incision in the tertiary hospital, the protuberance disappeared, and the placenta was found in the lower segment of the uterus cavity. The intercepted placenta showed a spontaneous resolution from the uterine wall and was removed intact. This case report details the typical presentation of placenta interception to make obstetricians aware of the possibility that carbetocin might lead to this adverse event.

NCAPH regulates gastric cancer progression through DNA damage response.

Gastric cancer (GC) is one of the most common devastating and deadly malignancies of the gastrointestinal tract in the world. GLOBOCAN data analysis showed that GC accounted for approximately 1,033,000 new cases of cancer and 78,200 deaths in 2018. Nonstructural maintenance of chromosomes (non-SMC) condensin I complex subunit H (NCAPH) is a regulatory subunit that encodes the non-SMC condensin I complex. Previous studies have demonstrated that NCAPH is highly expressed in multiple cancers. This study aimed to explore the function and potential mechanism of NCAPH in GC. Our study showed that NCAPH expression was significantly upregulated in The Cancer Genome Atlas (TCGA) and Oncomine datasets. Quantitative real-time polymerase chain reaction and western blotting were used to detect NCAPH expression in GC and paracarcinoma tissues. Cell Counting Kit-8 (CCK-8) and colony formation assays were used to examine cell proliferation. Cell scratch and Transwell invasion assays were performed to assess cell migration. In addition, western blotting was used to detect the expression of proteins related to the cell cycle, DNA damage repair, and epithelial-mesenchymal transition (EMT). Flow cytometry was applied for cell cycle and apoptosis detection. A xenograft model was employed to assess the effect of NCAPH in vivo. The results demonstrated that NCAPH expression was significantly increased in GC tissue samples and cell lines. Knockout of NCAPH notably inhibited cell proliferation, cell migration, cell invasion, cell cycle progression, and tumor growth in vitro and in vivo, and induced the G1-phase cell cycle arrest by regulating the DNA damage response. In addition, knockout of NCAPH promoted cell apoptosis and regulated the expression of EMT-related proteins. The results indicate that the knockout of NCAPH in GC cells inhibits proliferation and metastasis via the DNA damage response in vitro and in vivo. NCAPH plays an important role in GC and may be a potential therapeutic target for GC treatment.

The Tumor-Associated Macrophage-M2-Cancer Cell Complex and the Observation of Heterogeneous Modification of the Morphological Structure of Lung Adenocarcinoma.

OBJECTIVE: The aim of this study was to investigate the effect of the tumor-associated macrophage-m2-cancer cell complex (TAM-M2-CC) on the heterostructural modification of lung adenocarcinoma. METHODS: The expression of CD163+/CD68+ in macrophages in the microenvironment of 161 cases of lung adenocarcinoma was identified by dual immunohistochemistry, and the association between a TAM-M2-CC and its growth, as well as the histological changes in lung adenocarcinoma cells, was assessed. RESULTS: The morphological change of lung adenocarcinoma was related to the number of m2 phenotypes of the macrophages in the microenvironment of lung adenocarcinoma. TAM-M2-CCs were involved in the process of cancer cell recognition, association, and reconstruction. CONCLUSION: The microenvironment of lung adenocarcinoma can affect the phenotypic distinction of macrophages, and the polarization recruitment, zombification, and formation of a TAM-M2-CC, which can also affect the local differentiation of lung adenocarcinoma to a certain extent. The applicable pathogenesis needs to be verified and studied further.

Molecular dynamic simulation of performance of modified BAMO/AMMO copolymers and their effects on mechanical properties of energetic materials.

Based on molecular dynamic method, densities, mechanical behavior and mechanical performance of P(BAMO/ AMMO) (Polymer 1) and two novel modified P(BAMO/AMMO) (Polymer 2: containing amino group, Polymer 3: containing nitro group), and their effects on mechanical properties of four energetic materials are investigated, the main results are as follow: Polymer 2 (1.235 g/cm3, 240 ± 5 K) and Polymer 3: 1.281 g/cm3, 181 ± 3 K) possess higher densities and lower glass transition temperatures than Polymer 1 (1.229 g/cm3, 247 ± 4 K). The modification makes Polymer 1 difficult to expand, improves its mechanical properties, but has few effect on its diffusion coefficient at same temperature and state. In addition, three binders are compatible with TNT, HMX and CL-20, and may react with DNTF. All polymers particularly improve rigidity of four energetic materials, and enhance their ductility except Polymer 2 on TNT. The ability of Polymer 2 and Polymer 3 improving rigidity (except Polymer 3 on HMX) and ductility of TNT and HMX is inferior to that of Polymer 1, but it is contrary for CL-20 and DNTF (except Polymer 2 on rigidity of DNTF). Moreover, Polymer 2-based interfacial crystals exhibit higher rigidity than Polymer 3-based interfacial crystals.

CL-20-Based Cocrystal Energetic Materials: Simulation, Preparation and Performance.

The cocrystallization of high-energy explosives has attracted great interests since it can alleviate to a certain extent the power-safety contradiction. 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaaza-isowurtzitane (CL-20), one of the most powerful explosives, has attracted much attention for researchers worldwide. However, the disadvantage of CL-20 has increased sensitivity to mechanical stimuli and cocrystallization of CL-20 with other compounds may provide a way to decrease its sensitivity. The intermolecular interaction of five types of CL-20-based cocrystal (CL-20/TNT, CL-20/HMX, CL-20/FOX-7, CL-20/TKX-50 and CL-20/DNB) by using molecular dynamic simulation was reviewed. The preparation methods and thermal decomposition properties of CL-20-based cocrystal are emphatically analyzed. Special emphasis is focused on the improved mechanical performances of CL-20-based cocrystal, which are compared with those of CL-20. The existing problems and challenges for the future work on CL-20-based cocrystal are discussed.

Prevalence and Population Genetics Analysis of Enterocytozoon bieneusi in Dairy Cattle in China.

Enterocytozoon bieneusi, an obligate intracellular pathogen, can infect various hosts. In this study, 3527 dairy cattle fecal specimens were collected from different geographic locations in China (including 673 from Shandong province, 1,440 from Guangdong province and 1,414 from Gansu province) and examined for the presence of E. bieneusi using polymerase chain reactions targeting the ribosomal internal transcribed spacer (ITS). The dominant genotypes identified were further subtyped by multilocus sequence typing. The overall prevalence of E. bieneusi was 14.2% (501/3527), with a significant difference in prevalence among the different geographical locations (P < 0.001). Our logistic regression analysis showed that all four variables (farming model, location, age, and clinical manifestations) had strong effects on the risk of contracting E. bieneusi. Sequence analysis revealed 11 genotypes: eight known genotypes (J, I, BEB4, BEB10, D, EbpC, CM19, and CM21) and three novel genotypes (named here as CGC1, CGC2, and CGC3). Genotypes J and I, the commonest, were found on all farms across the three provinces. Our linkage disequilibrium analysis showed a clonal population structure in the E. bieneusi dairy cattle population but the ITS genotypes had different population structures. Phylogenetic and haplotype network analysis showed the absence of geographical segregation in the E. bieneusi dairy cattle populations. Instead, they revealed the presence of host adaptation to the E. bieneusi populations in various animals. Our findings augment the current understanding of E. bieneusi transmission dynamics.

Diffuse biliary peritonitis secondary to rupture of metastatic liver adenocarcinomas after drug-eluting bead transcatheter arterial chemoembolization: a case report.

Transcatheter arterial chemoembolization (TACE) has become one of the first-line standard treatments for intermediate-advanced hepatocellular carcinoma, as well as an effective treatment for metastatic hepatic carcinoma. The majority of TACE-related complications are mild and acceptable to patients. Compared with conventional (C)-TACE, drug-eluting bead (DEB)-TACE allows permanent embolization of blood vessels, a slow continuous release of anti-tumour drugs in a locally targeted manner, and reduction of the systemic release of anti-tumour drugs, so that their adverse effects are significantly reduced. The general consensus is that DEB-TACE is safer and better tolerated by patients than C-TACE because serious complications after DEB-TACE are rarely reported. This current case report describes a rare case of diffuse biliary peritonitis secondary to rupture of a hepatic tumour after DEB-TACE. After the procedure, the patient presented with progressively worsening upper abdominal pain. As conventional management methods for the suspected tumour rupture failed, an emergency laparotomy was performed to remove the metastatic mass of differentiated hepatic adenocarcinoma. The patient remains under surveillance with no further complications. In our opinion, although DEB-TACE is safe and rarely has serious complications, caution should be exercised when this method is used to treat tumours that are located close to the liver surface.

Transformation of Combustion Nanocatalysts inside Solid Rocket Motor under Various Pressures.

In this paper, the dependences of the morphology, particle sizes, and compositions of the condensed combustion products (CCP) of modified double-base propellants (1,3,5-trimethylenetrinitramine (RDX) as oxidizer) on the chamber pressure (<35 MPa) and nickel inclusion have been evaluated under a practical rocket motor operation. It has been shown that higher pressure results in smaller average particle sizes of the CCPs. The CCPs of Ni-containing propellants have more diverse morphologies, including spherical particles, large layered structures, and small flakes coated on large particles depending on the pressure. The specific surface area (SSA) of CCPs is in the range of 2.49 to 3.24 m² g-1 for propellants without nickel are less dependent on the pressure, whereas it is 1.22 to 3.81 Ni-based propellants. The C, N, O, Al, Cu, Pb, and Si are the major elements presented on the surfaces of the CCP particles of both propellants. The compositions of CCPs from Ni-propellant are much more diverse than another one, but only three or four major phases have been found for both propellants under any pressure. The metallic copper is presented in CCPs for both propellants when the chamber pressure is low. The lead salt as the catalyst has been transformed in to Pb(OH)Cl as the most common products of lead-based catalysts with pressure lower than 15 MPa. When pressure is higher than 5 MPa, the nickel-based CCPs has been found to contain one of the following crystalline phases: Pb2Ni(NO2)6, (NH4)2Ni(SO4)2·6H2O, C2H2NiO4·2H2O, and NiO, depending on the pressure.

Widespread occurrence of Cryptosporidium infections in patients with HIV/AIDS: Epidemiology, clinical feature, diagnosis, and therapy.

Cryptosporidium infection is a serious threat for HIV/AIDS patients, causing severe diarrhea and even death. The overall prevalence of Cryptosporidium in HIV/AIDS patients was calculated as approximately 8.69% (7,799/89,724), with higher prevalence observed in individuals with diarrhea, individuals with low CD4+ T-lymphocyte counts, and antiretroviral therapy-naïve individuals. Cryptosporidium infection was not significantly associated with patient age or gender, national development levels, or continent of residence. Over the period from 2007 to 2017, Cryptosporidium prevalence was 10.09% (3,282/32,517); this figure was higher than that observed in each of the previous observation periods (1985-1995 and 1996-2006), suggesting that the prevalence of cryptosporidiosis has been increasing over time in HIV/AIDS patients. Ten Cryptosporidium species and genotypes have been identified from 1,252 isolates, with C. hominis, C. parvum, and C. meleagridis accounting for 93.53% of infections. Five subtypes each of C. hominis (Ia, Ib, Id, Ie, and If), C. parvum (IIa to IIe), and C. meleagridis (IIIa to IIIe) have been described by sequence analyses of the 60-kDa glycoprotein (gp60) gene. Variation in the clinical manifestations observed in HIV/AIDS patients might be attributed to infection by different Cryptosporidium species, genotypes and subtypes, as well as different sites of infection. New molecular and immunological diagnostic techniques are in development or already commercially available. High-throughput screening methods for development of new or repurposed therapeutics as well as novel parasite genetic manipulation strategies offer hope for improving human cryptosporidiosis therapies. Painstaking efforts by researchers as well as support from governments and funding agencies will be required to make lasting achievements in this field.

Treatment of an incarcerated inguinal hernia associated with abdominal tuberculosis in an adult patient.

The incidence of tuberculosis is increasing worldwide, especially in developing countries. The prevalence of abdominal tuberculosis has been found to be as high as 12% in people with extrapulmonary tuberculosis. Peritoneal thickening and intestinal adhesions can occur in patients with abdominal tuberculosis. Inguinal hernias are extremely rare in people with abdominal tuberculosis; only 11 cases have been reported in the English-language literature, half of which involved pediatric patients. No definitive guideline on the management of such cases is available. In this report, we describe the unusual finding of an incarcerated inguinal hernia in an adult with abdominal tuberculosis and propose a therapy to treat this complicated disease based on our successful experience.

Novel genotypes and multilocus genotypes of Enterocytozoon bieneusi in pigs in northwestern China: A public health concern.

Enterocytozoon bieneusi, the most important and common microsporidian species, inhabits in most animals and humans causing diarrhea and systemic diseases. The objectives of the present study were to examine the prevalence and genetic variability of E. bieneusi in pigs in Shaanxi province, northwestern China. A total of 560 pig faecal samples were collected from five different farms in Shaanxi province and molecularly characterized using multilocus genotyping (MLST) technology. High E. bieneusi infection rate (78.9%) was observed in these samples. 12 known and 22 possible novel ITS genotypes were identified, with the novel SZZD1 as the predominant genotype distributed in all age groups and pig farms. 32 (including 11 known and 21 novel ones) of them belong to the zoonotic group 1. MLST analysis showed that 109 ITS positive samples formed 87 distinct multilocus genotypes (MLGs). An incomplete linkage disequilibrium (LD) and clonal genetic structure of E. bieneusi were found in pigs in Shaanxi province. These findings indicated the complex population structures of E. bieneusi in pigs in Shaanxi province and provided baseline data for better understanding of the epidemiological status of E. bieneusi in this province.

A distal ileum malignant peripheral nerve sheath tumor causing intussusception in a patient in China: a case report.

BACKGROUND: Malignant peripheral nerve sheath tumors (MPNSTs) arise from a peripheral nerve or display nerve sheath differentiation. Most MPNSTs typically originate on the trunk, extremities, head, neck, and paravertebral regions. Gastrointestinal MPNSTs are rare entities with only 10 cases reported worldwide in the literatures. CASE PRESENTATION: Here, we report the first Chinese case of a malignant peripheral nerve sheath tumor of the distal ileum presenting as intussusception. A 53-year-old female patient without pathological antecedent for neurofibromatosis was admitted with pain in the right lower abdomen and multiple episodes of vomiting for 1 week. Preoperative diagnosis was intussusception with a contrast-enhanced computed tomography scan (CECT) of the abdomen showing characteristic target sign. Due to difficulty reducing the ileum-colon intussusception, right hemicolectomy with ileocolostomy was performed. Histopathology was suggestive of low-grade MPNST. The patient received postoperative care and was followed up for 9 months. There is no sign of tumor recurrence and metastatic disease. CONCLUSIONS: This case is unique in terms of a rare tumor presenting with unusual complication.

[Clinical analysis of 29 cases with neuroendocrine neoplasm in the digestive system].

OBJECTIVE: To investigate the diagnosis and treatment of neuroendocrine neoplasm (NEN) in the digestive system. METHODS: Clinical data of 29 patients with NEN from January 2000 to December 2012 in The First Affiliated Hospital of Dalian Medical University were analyzed retrospectively and the prognosis was evaluated according to the new WHO classification. RESULTS: There were 19 males and 10 females and the average age was 46.5 years. All the patients had no clinical manifestations of carcinoid syndrome, and they all received surgical treatment. Two cases were gastric neuroendocrine carcinoma(NEC), who received radical total gastrectomy and distal gastric resection respectively. Three cases had neoplasm in the duodenum, including 2 NEC and 1 neuroendocrine tumor(NET), and they all underwent Whipple's procedure. Two cases were small intestine NEC, who received partial small intestine resection. Three cases had neoplasm in the appendix, including 1 NEC treated with right hemicolectomy and 2 NET with appendectomy. One case was ascending colon NEC, who received right hemicolectomy. Eighteen cases had neoplasm in the rectum, including 4 NEC treated with low anterior resection and abdominoperineal resection respectively, and 14 cases of NET underwent low anterior resection, local resection, and endoscopic resection respectively. The 1- and 3- year survival rates of 13 NEC cases were 38.4% and 7.7% respectively. The 5-year survival rate of 16 NET cases was 81.3%. CONCLUSIONS: NEN of digestive system is located mainly in the rectum and the clinical symptom is unspecific. Radical resection of NEN is the preferred treatment. The prognosis of NEC is poor, and that of NET is better.

A novel colorimetric HSO4(-) sensor in aqueous media.

A novel and sensitive anion receptor 3, bearing Schiff base structure, nitrophenyl azobenzol and carboxyl groups, was developed and characterized as a single chemosensor for the recognition of HSO(4)(-) anion. The different responses of UV-vis spectra and color changes of 3 could be applied to the recognition for HSO(4)(-) over other anions such as F(-), CI(-), Br(-), I(-), AcO(-), H(2)PO(4)(-) and CIO(4)(-) by the naked eye. Furthermore, the anion binding interaction of receptor-anion was also studied using UV-vis and (1)H NMR titration which revealed that 3 displayed a remarkable binding ability for the HSO(4)(-) with an association constant K(a)=6.59×10(4) M(-1). And the detection limitation of HSO(4)(-) with the receptor 3 was 2.0×10(-6) mol L(-1) in aqueous solution. Most importantly, the qualitative detection of HSO(4)(-) using receptor 3 was attempted with test kit which was made from receptor 3.

Mercapto thiadiazole-based sensor with colorimetric specific selectivity for AcO- in aqueous solution.

A novel acetate selective anion sensor 3 based on azophenol and mercapto thiadiazole had been designed and synthesized. Sensor 3 behaves a single selectivity and sensitivity in the recognition for AcO(-) anion over other anions such as F(-), Cl(-), Br(-), I(-), H(2)PO(4)(-), HSO(4)(-) and ClO(4)(-) by naked-eyes and UV-vis spectra changes in aqueous solution (H(2)O/DMSO, 5:5, v/v). The color of the solution containing sensor 3 had an obvious change from colorless to orange only after the addition of AcO(-) in aqueous solution while other anions did not cause obvious color change. (1)H NMR titration results revealed that the binding process includes two steps: (i) hydrogen bonding interactions (for small quantities of acetate) and (ii) proton transfer between the sensor 3 and the coordinated anion (for high quantities of acetate). The association constant K(a) was 7.35×10(3) M(-1). The detection limitation of AcO(-) with the sensor 3 was 1.0×10(-6) mol L(-1).

[Hepatitis B surface antigen terminates codon bias selection].

OBJECTIVE: To investigate the existence condition of hepatitis B surface antigen(HBsAg) termination codon bias. METHODS: A total of 174 reference sequences of all kinds of Hepatitis B virus(HBV) genotypes were chosen from GenBank, and compared by BioEdit. Then secondary structure of RNA was constructed and analyzed together. RESULTS: (1) There were two types of HBsAg termination codon: TAA and TGA in 174 reference sequences. TAA was in 124 cases (71.26%); and TGA in 50 cases (28.74%). (2) There was codon bias selection in HBsAg termination codon, and it could affect the secondary structure of RNA and amino acid sequence encoding protein. CONCLUSION: HBsAg termination codon bias exists and may be related to RNA structure and the conservation of protein function in the evolutionary progress.

[The distribution of hepatitis C virus genotype 1a in Yanbian area].

OBJECTIVE: To investigate the distribution of Hepatitis C Virus (HCV)genotype 1a in Yanbian area, Jilin province. METHODS: The genotypes of the serum specimens of 47 patients with HCV from Yanbian area were determined by Scheme ABC of RFLP based on HCV 5' noncoding region (5'NCR). The samples of type 1a (Y2, Y4, Y6, and Y8) were amplified from the 5'NCR and NS5B regions by RT-PCR, and then sequenced directly. These sequences were subjected to phylogenetic analysis with 27 reference sequences of HCV complete genomes from GenBank. RESULTS: 44 specimens were HCV RNA positive, among which 19 specimens (43.2%) were of the type 1a/1b, 12 (27.3%) were of the type 1b, 8 (18.2%) were of the type 2a/1b, 4 (9.1%) were of the type 1a, and 1 (2.3%) was of the type 2a, however, the genotypes 2b and 3 approximately 6 lacked. The phylogenetic analysis for 1a samples showed that according to 5'NCR they belonged to type 1a, while on NS5B belonging to type 1b. The most nucleotide identity of 5'NCR was respectively 0.990, 0.990, 0.990, and 0.990 between Y2, Y4, Y6, Y8 and the isolate HC-J1 (genotype 1a), while that of NS5B was respectively 0.936, 0.957, 0.936, and 0.936 between Y2, Y4, Y6, Y8 and the isolate HC-J4 (genotype 1b). CONCLUSION: In Yanbian area the distribution of HCV genotype is different from those in other areas and 1a/1b has even replaced 1b as the most HCV genotype here. The results of genotyping 1a on 5'NCR and NS5B are completely inconsistent. This phenomenon may be the consequence of recombination in evolution.