EgSeverin and Eg14-3-3zeta from Echinococcus granulosus are potential antigens for serological diagnosis of echinococcosis in dogs and sheep.

Cystic echinococcosis (CE) is a zoonotic parasitic disease caused by the metacestode larva of Echinococcus granulosus. In this study, two-dimensional gel electrophoresis (2-DE) coupled with immunoblot analysis revealed that E. granulosus severin and 14-3-3zeta proteins (named EgSeverin and Eg14-3-3zeta, respectively) might be two potential biomarkers for serological diagnosis of echinococcosis. The recombinant EgSeverin (rEgSeverin, 45 kDa) and Eg14-3-3zeta (rEg14-3-3zeta, 35 kDa) were administered subcutaneously to BALB/c mice to obtain polyclonal antibodies for immunofluorescence analyses (IFAs). And IFAs showed that both proteins were located on the surface of protoscoleces (PSCs). Western blotting showed that both proteins could react with sera from E. granulosus-infected sheep, dog, and mice. Indirect ELISAs (rEgSeverin- and rEg14-3-3zeta-iELISA) were developed, respectively, with sensitivities and specificities ranging from 83.33% to 100% and a coefficient of variation (CV %) of less than 10%. The rEgSeverin-iELISA showed cross-reaction with both E. granulosus and E. multilocularis, while the rEg14-3-3zeta-iELISA showed no cross-reaction with other sera except for the E. granulosus-infected ones. The field sheep sera from Xinjiang and Qinghai were analyzed using rEgSeverin-iELISA, rEg14-3-3zeta-iELISA, and a commercial kit respectively, and no significant differences were found among the three methods (p > 0.05). However, the CE positive rates in sheep sera from Qinghai were significantly higher than those from Xinjiang (p < 0.01). Overall, the results suggest that EgSeverin and Eg14-3-3zeta could be promising diagnostic antigens for E. granulosus infection.

Effect of Daratumumab combined with Chemotherapy on Immune Function in Patients with Relapsed/Refractory Multiple Myeloma and Observation of its Clinical Efficacy.

Objective: To evaluate the clinical efficacy and immune function of Daratumumab combined with chemotherapy in patients with relapsed/refractory multiple myeloma (RRMM). Methods: Eighty patients with RRMM treated in Xingtai People's Hospital from January, 2020 to December, 2021 were randomly divided into two groups. Patients in the study group were treated with Daratumumab combined with PAD regimen, while patients in the control group were provided with PAD regimen alone. Further comparison was performed on the therapeutic effects, adverse drug reactions, the levels of T lymphocyte subsets CD3+, CD4+, CD8+ and CD4+/CD8+, the positive expression rate of CD38 and the expression level of Notch-1 on the membrane of plasma cells between the two groups. Results: The overall response rate in the study group (67.50%) was significantly better than that in the control group (45.00%). There was no significant difference in the incidence of adverse reactions between the two groups. After treatment, the reviewed levels of CD3+, CD4+ and CD4+/CD8+ were obviously higher in the study group than those in the control group, while the positive expression rate of CD38 and the expression level of Notch one on the membrane of plasma cells were both lower than those in the control group (p<0.05). Conclusion: Daratumumab combined with a PAD regimen is a safe and effective approach that has a definite curative effect on patients with RRMM, which can improve immune function significantly and result in no significant increase in adverse reactions.

Temporal metabolic profiling of erythrocytes in mice infected with Babesia microti.

BACKGROUND: Babesiosis is an emerging zoonosis worldwide that is caused by tick-borne apicomplexans, Babesia spp., which threatens the health of domesticated and wild mammals and even humans. Although it has done serious harm to animal husbandry and public health, the study of Babesia is still progressing slowly. Until now, no effective anti-Babesia vaccines have been available, and administration of combined drugs tends to produce side effects. Therefore, non-targeted metabolomics was employed in the present study to examine the temporal dynamic changes in the metabolic profile of the infected erythrocytes. The goal was to obtain new insight into pathogenesis of Babesia and to explore vaccine candidates or novel drug targets. METHODS: C57BL/6 mice were infected with B. microti and erythrocytes at different time points (0, 3, 6 , 9, 12, and 22-days post-infection) were subjected to parasitemia surveillance and then metabolomics analysis using liquid chromatography-mass spectrometry (LC-MS). Multivariate statistical analyses were performed to clearly separate and identify dysregulated metabolites in Babesia-infected mice. The analyses included principal components analysis (PCA) and orthogonal partial least squares-discrimination analysis (OPLS-DA). The time-series trends of the impacted molecules were analyzed using the R package Mfuzz and the fuzzy clustering principle. The temporal profiling of amino acids, lipids, and nucleotides in blood cells infected with B. microti were also investigated. RESULTS: B. microti infection resulted in a fast increase of parasitemia and serious alteration of the mouse metabolites. Through LC-MS metabolomics analysis, 10,289 substance peaks were detected and annotated to 3,705 components during the analysis period. There were 1,166 dysregulated metabolites, which were classified into 8 clusters according to the temporal trends. Consistent with the trend of parasitemia, the numbers of differential metabolites reached a peak of 525 at 6-days post-infection (dpi). Moreover, the central carbon metabolism in cancer demonstrated the most serious change during the infection process except for that observed at 6 dpi. Sabotage occurred in components involved in the TCA cycle, amino acids, lipids, and nucleotide metabolism. CONCLUSION: Our findings revealed a great alteration in the metabolites of Babesia-infected mice and shed new light on the pathogenesis of B. microti at the metabolic level. The results might lead to novel information about the mechanisms of pathopoiesis, babesisosis, and anti-parasite drug/vaccine development in the future.

Seroprevalence and the Risk Factor of Toxoplasma gondii Infection to Slaughter Pigs in Chongqing, China.

Toxoplasma gondii can infect all mammals, including humans, and can cause serious public health problems and economic losses. Pork is considered an important source of infection for humans, and seroepidemiological surveys are used to assess the level of infection in pig herds. To understand the current seroprevalence and potential risk factors of T. gondii in pigs in Chongqing, a total of 1221 serum samples collected from seven slaughterhouses in five districts from 2015 to 2019 were analyzed for antibodies against the protozoan by enzyme-linked immunosorbent assay. The overall seropositive rate for T. gondii antibodies in Chongqing was 11.1%. The rate varied among the different districts (9.8-15.2%), slaughterhouses (8.0-18.4%), seasons (8.1-14.6%), and years (6.3-14.7%). These results suggest that the season and year were potential risk factors for T. gondii infection in pigs of Chongqing. The study provides prevalence and risk factor data that may help manage livestock and human infections in downstream areas. The Clinical Trial Registration number was SV-20150605-01.

The divergent response of vegetation phenology to urbanization: A case study of Beijing city, China.

Characterizing the relationship between vegetation phenology and urbanization indicators is essential to understand the impacts of human activities on urban ecosystems. In this study, we explored the response of vegetation phenology to urbanization in Beijing (China) during 2001-2018, using impervious surface area (ISA) and the information of urban-rural gradients (i.e., concentric rings from the urban core to surrounding rural areas) as the urbanization indicators. We found the change rates of vegetation phenology in urban areas are 1.3 and 1.1 days per year for start of season (SOS) and end of season (EOS), respectively, about three times faster than that in forest. Moreover, we found a divergent response of SOS with the increase of ISA, which differs from previous results with advanced SOS in the urban environment than surrounding rural areas. This might be attributed to the mixed land cover types and the thermal environment caused by the urban heat island in the urban environment. Similarly, a divergent pattern of phenological indicators along the urban-rural gradient shows a non-linear response of vegetation phenology to urbanization. These findings provide new insights into the complicated interactions between vegetation phenology and urban environments. High-resolution weather data are required to support process-based vegetation phenology models in the future, particularly under different global urbanization and climate change scenarios.

miR-497-5p induces apoptosis in K562 cells by downregulating ROCK1.

OBJECTIVE: To validate the role of miR-497-5p in apoptosis in K562 cells by targeting Rho-associated kinase isoform 1 (ROCK1). METHODS: From January, 2017 to February, 2019, 57 patients with chronic myeloid leukemia (CML) treated in our hospital were included in patient group, and 50 healthy individuals were recruited as control group. miR-497-5p level in peripheral blood was quantitated using qRT-PCR. After transfecting with miR-497-5p overexpression vector and ROCK1 inhibitor, K562 cells were monitored in terms of proliferation (CCK8 assay), migration and invasion (Transwell), and apoptosis (flow cytometry). Binding loci between miR-497-5p and ROCK1 were predicted, and the targeting relationship was confirmed (dual-luciferase reporter (DLR) assay). RESULTS: miR-497-5p was poorly expressed in CML (P < 0.05). Forced overexpression of miR-497-5p or inhibition of ROCK1 suppressed malignant processes (proliferation, proliferation, migration and invasion) in K562 cells and induced apoptosis (P < 0.05). DLR assay revealed a decreased luciferase activity after miR-497-5p binding to ROCK1 (P < 0.05). CONCLUSION: miR-497-5p induces apoptosis in K562 cells by downregulating ROCK1.

miR-506 in patients with chronic myeloid leukemia and its effect on apoptosis of K562 cells.

OBJECTIVE: To explore the expression of miR-506 in chronic myeloid leukemia (CML) and its influence on the biological function of CML cells. METHODS: Altogether 84 CML patients from February 2012 to September 2014 were obtained as the observation group (OG), and 71 healthy people were taken as the control group (CG). miR-506 was tested using RT-qPCR, and the 5-year survival of patients with high and low expression of miR-506 was compared with the median value of miR-506 as the limit. ROC curve was applied to detect the value of miR-506 in diagnosing CML and predicting the 5-year survival of patients, and K562 cell line was transfected with miR-506 inhibitor and miR-506 mimic for observing its effects on the cell proliferation and apoptosis. RESULTS: miR-506 in CML patients was evidently lower than that in healthy people, the AUC of diagnosis of miR-506 was 0.883, the total survival of patients with low miR-506 was evidently lower than those with high miR-506, and the AUC of predicted survival of patients was 0.778. The proliferation of cells transfected with miR-506 inhibitor was promoted, the apoptosis and the survival rate reduced. CONCLUSION: miR-506 is evidently reduced in CML, and may be applied as a diagnostic and predictive treatment for CML and 5-year related survival; it can also can hinder the viability of K562 cells and promote apoptosis.

Molecular detection and genetic characterization of Toxoplasma gondii in pork from Chongqing, southwest China.

Raw or undercooked meat is an important source of Toxoplasma gondii infection in China, but there is little research data on these infections in Chongqing. This study determined the prevalence of T. gondii, and its genotypes, in pork. A total of 1,223 diaphragm muscle samples were collected from eight slaughterhouses and 79 markets and detected by PCR amplification of the ITS gene. All of the positive samples were used for genotype identification by PCR-RFLP with 11 genetic markers. The total positive rate of T. gondii in Chongqing pork was 8.7%, and differences in T. gondii infection rates were found between different districts (0%-23.3%), seasons (e.g., 4.3% from Spring, 7.3% from Summer, 11.4% from Autumn, 12.0% from Winter) and years (2.7%-14.3%). Six samples were successfully genotyped, of which one was identified as ToxoDB#9 and five were ToxoDB#9-like. This was the first continuous study about the prevalence of T. gondii in pork in Chongqing for several years. Slaughterhouses in different districts, pork source, farm scale, season and year were potential risk factors for T. gondii contamination by the univariate logistic regression, and using multivariate logistic regression districts, pork source and year were the independent risk factor. These data may help reducing the levels of toxoplasmosis in pigs and humans in Chongqing.

Seroprevalence and associated risk factors of Toxoplasma gondii infection in yaks (Bos grunniens) on the Qinghai-Tibetan Plateau of China.

Toxoplasma gondii is an intracellular parasite that is extensively prevalent globally. Studies have indicated the presence of T. gondii infection in animals in some provinces of China, but little is known about T. gondii infection in yaks (Bos grunniens) on the Qinghai-Tibetan Plateau. In the current study, to determine the seroprevalence and associated risk factors of T. gondii, a total of 2784 serum samples were collected from 18 different sampling sites in eight counties of the Qinghai and Tibet regions of China from 2018 to 2019. Serum antibodies against T. gondii were detected in 261 yaks (9.38%) via enzyme-linked immunosorbent assay (ELISA). We found that seroprevalence differed significantly among different counties (ranging from 5.41% in Gangcha to 19.79% in Datong), by year in the Tibet Autonomous Region (from 2.34% in 2018 to 13.24% in 2019), and by age (from 5.59% in 0 < year ≤ 1 to 11.76% in year > 7) (p < 0.05). Climate, geographical conditions, and age are the main factors influencing T. gondii infection in yaks in these regions. Therefore, our study provides a data reference for public health and prevention of yak toxoplasmosis.

TITLE: Séroprévalence et facteurs de risque associés à l'infection par Toxoplasma gondii chez les yaks (Bos grunniens) du plateau Qinghai­Tibet en Chine. ABSTRACT: Toxoplasma gondii est un parasite intracellulaire largement répandu dans le monde. Des études ont indiqué la présence d'une infection par T. gondii chez les animaux dans certaines provinces de Chine, mais on connaît peu l'infection par T. gondii chez les yaks (Bos grunniens) sur le plateau Qinghai­Tibet. Dans la présente étude, pour déterminer la séroprévalence et les facteurs de risque associés de T. gondii, un total de 2784 échantillons de sérum ont été prélevés sur 18 sites d'échantillonnage différents dans huit comtés des régions du Qinghai et du Tibet en Chine entre 2018 et 2019. Des anticorps sériques contre T. gondii ont été détectés par dosage immuno-enzymatique (ELISA) chez 261 yaks (9,38 %). Nous avons constaté que la séroprévalence différait considérablement entre les différents comtés (allant de 5,41 % à Gangcha à 19,79 % à Datong), d'une année à l'autre dans la région autonome du Tibet (de 2,34 % en 2018 à 13,24 % en 2019), et par âge (de 5,59 % pour les animaux de moins d'un an à 11,76 % pour ceux âgés de plus de 7 ans) (p < 0,05). Le climat, les conditions géographiques et l'âge sont les principaux facteurs influençant l'infection à T. gondii chez les yaks de ces régions. Par conséquent, notre étude fournit des données de référence pour la santé publique et la prévention de la toxoplasmose du yak.

Expression and functionality of allergenic genes regulated by simulated gastric juice in Anisakis pegreffii.

To better understand the molecular mechanisms underlying allergens and parasite immunity and discover the stage-enriched gene expression of fish-borne zoonotic nematodes in the stomach, we used RNA-seq to study the transcriptome profiles of Anisakis pegreffii (Nematoda: Anisakidae, AP) in simulated gastric juice. Mobile L3 larvae were incubated in simulated medium at 37 °C in 5% CO2 (AP-GJ) and the control group larvae were collected in PBS under the same conditions (AP-PBS). We found that the sequences of A. pegreffii were highly similar to Toxocara canis sequences. Among the transcripts, there would be 138 up-regulated putative genes and 251 down-regulated putative genes in AP-GJ group. Several lipid binging-related genes were more highly expressed in AP-GJ larvae. Moreover, 17 allergen genes were up-regulated and 29 were down-regulated in AP-GJ larvae. Eleven allergen genes belonged to one or more of the following three categories: biological process, cellular component, and molecular function. According to KEGG analysis, the main pathways that were represented included protein processing in transcription, immune system, cancer, and infectious disease. In particular, the most significant changes in the expression of parasite-derived allergen products occurred in AP-GJ larvae. This study helps us to extend our understanding of the biology of the fish-borne zoonotic parasite A. pegreffii and could be helpful for more precise risk assessment and providing guidelines for allergic consumers.

Low prevalence of spargana infection in farmed frogs in the Yangtze River Delta of China.

Frogs are the main source of infection for human sparganosis. In this study, the prevalence and pathogenicity of plerocercoid larvae (sparganum) in frogs collected from the Yangtze River Delta in East China were investigated. A total of 386 frogs belonging to five species were purchased from farmers' markets across all three provincial level areas in the Yangtze River Delta region. The overall prevalence was 4.9% (19/386), and 39 spargana were detected visually, with the intensity ranging from 1 to 11. The spargana infection rate was 7.7% (11/143) in Jiangsu Province and 4.4% (8/181) in Shanghai City, while no spargana infection was detected in Zhejiang Province. In five tested frog species, only Rana nigromaculata and R. limnocharis were found to harbor spargana infection, with a prevalence of 7.7% (13/168) and 6.3% (6/95), respectively. There was no significant difference among the months of the experimental period, July to September. The spargana mostly parasitized the muscle tissues of frogs, especially in the hind legs. All the spargana were identified by molecular analysis based on cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes, and all plerocercoids were Spirometra erinaceieuropaei. Nine mice were infected orally with 1 to 3 scoleces, and 77.8% (14/18) of plerocercoids were found in mice at the 30th day post infection. No obvious clinical symptoms were observed in the mice; however, histopathological analysis showed an inflammatory cellular response in all tissues except intestinal tissue. Hematologic analysis showed an increased number of white blood cells (WBCs) at the 18th day post infection. These results indicated that R. nigromaculata and R. limnocharis are a potential source of zoonotic sparganosis in the Yangtze River Delta of China, and farmed frogs may substantially reduce zoonotic risk as compared to eating wild frogs. Our findings will provide data for frog food safety and prevention and control of sparganosis in the region.

Seroprevalence of Toxoplasma gondii infection in slaughter pigs in Shanghai, China.

Toxoplasma gondii is a pathogen that seriously threatens the health of humans and animals. However, the current infection status of T. gondii in slaughter pigs in Shanghai is still not clear. To investigate the seroprevalence of T. gondii infection and analyze the prevalence factors associated with the parasite infection, 1158 serum samples were collected from five slaughterhouses in three districts between 2015 and 2018. Serum antibodies against T. gondii were detected in 160 pigs (13.8%) by enzyme-linked immunosorbent assay (ELISA). Additionally, seroprevalence rates differed among different districts (ranging from 4.0% in JD-2 to 17.6% in JD-1), seasons (ranging from 6.7% in winter to 17.8% in autumn), and years (ranging from 8.0% in 2016 to 26.8% in 2015). Region, season, and year were the main factors affecting T. gondii infection in these pigs. There were few reports on serological monitoring of T. gondii in Shanghai slaughterhouses between 2015 and 2018, and the number of infections had steadily increased over the past several consecutive years. Therefore, our data are helpful to understand the epidemic status of T. gondii in Shanghai, which will strengthen the prevention and treatment of swine toxoplasmosis.

G allele of rs7853346 polymorphism in PTENP1 enhances the proliferation of multiple myeloma cancer stem cells by promoting the expression of PTENP1 and its downstream signaling molecules.

Noncoding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), are shown to be associated with the pathogenesis of various diseases, such as multiple myeloma (MM). Therefore, the aim of this study was to explore the role of rs7853346 polymorphism in PTENP1, and its downstream signaling molecules, in the pathology of MM. Forty-three multiple myeloma patients and 35 healthy subjects were recruited and divided into CC, CG, and GG groups according to their genotypes of rs7853346 polymorphism in PTENP1. Real-time polymerase chain reaction (PCR), Western-blot analyses and immunohistochemistry assays were utilized to compare the expression of PTENP1, miR-19b, and TSC1 between different groups. In addition, the relationship between PTENP1, miR-19b, and TSC1, as well as the role of PTENP1 in MM, was explored. Higher levels of PTENP1 and TSC1 mesenger RNA (mRNA) were observed in the MM group, along with a lower level of miR-19b. Moreover, the protein level of TSC1 in the MM group was evidently upregulated compared to that in the negative control (NC) group. Meanwhile, compared to the CG and GG groups, the CC group showed higher levels of PTENP1 and TSC1 mRNA, as well as a lower level of miR-19b. According to the results of real-time PCR, a negative correlation with a correlation coefficient of -0.05 was established between PTENP1 and miR-19b expression. Similarly, a negative correlation with a correlation coefficient of -0.05 was also established between miR-19b and TSC1 expression. In addition, the transfection of pcDNA-PTENP1 or anti-miR-19b into cells significantly suppressed miR-19b expression but obviously increased TSC1 expression. The G allele of rs7853346 polymorphism enhances the proliferation of MM cancer stem cells by promoting the expression of PTENP1 as well as its downstream signaling molecules. Therefore, rs7853346 may become a novel biomarker for the diagnosis and treatment of MM.

Prevalence and genetic diversity of Enterocytozoon bieneusi in sheep in China.

BACKGROUND: Enterocytozoon bieneusi is a common species of microsporidia that not only influences human health but also threatens animal productive performance and value. However, there have been no systematic studies of the prevalence of E. bieneusi in sheep in China. RESULTS: A total of 953 fecal specimens were collected from sheep from 11 provinces across five regions of China and analyzed for E. bieneusi by nested PCR targeting the ribosomal internal transcribed spacer (ITS). Enterocytozoon bieneusi infections were detected in four regions, with an overall infection rate of 20.4% (194/953). The highest infection rate was detected in pre-weaned lambs (25.0%), followed by post-weaned lambs (22.2%) and adult sheep (14.6%). Enterocytozoon bieneusi was found in nine of the 11 tested provinces, with infection rates between 2.9-51.7%. Eleven genotypes were identified based on ITS analysis, including seven known genotypes (BEB6, CHG1, CHG3, CHS7, CHS8, COS-I and NESH5) and four novel genotypes (CHHLJS1, CHHLJS2, CHNXS1 and CHXJS1). All 11 genotypes were clustered into group 2, and the zoonotic genotype BEB6 was the dominant genotype (n = 129, 66.5%) in sheep. CONCLUSION: The prevalence of E. bieneusi was studied in five regions representing most areas where sheep are bred in China. This is the first report of E. bieneusi infection in sheep for seven Chinese provinces. Geographical differences were detected in the distribution of E. bieneusi genotypes, but no differences were found among sheep in different age groups. The zoonotic genotype BEB6 was the dominant genotype, indicating that sheep are a potential source of zoonotic microsporidiosis in China. These results improve our knowledge of the epidemiology of E. bieneusi in sheep in China.

Sheep as a Potential Source of Zoonotic Cryptosporidiosis in China.

In this study, we assessed the prevalence and genetic characteristics of Cryptosporidium in sheep from 10 provinces in China. Fecal samples from 1,035 sheep originating from 16 farms were collected, and 295 (28.5%) were found to be Cryptosporidium positive by nested PCR. Cryptosporidium was detected at all farms, with infection rates between 5.7% and 50.0%. Three Cryptosporidium species were identified, including Cryptosporidium xiaoi (73.2%, 216/295), Cryptosporidium ubiquitum (21.7%, 64/295), and Cryptosporidium parvum (5.1%, 15/295). The distribution of Cryptosporidium species differed by province and by farm. All three species were detected in lambs and adult sheep but the highest infection rate was found in postweaned lambs. All three species were detected in all four seasons, with the highest prevalence found in autumn. Four C. parvum subtypes (IIaA15G2R1, IIaA17G2R1, IIdA18G1, and IIdA19G1) and one C. ubiquitum subtype (XIIa) were identified. For most provinces in this study, we are not aware of a previously published description or molecular characterization of Cryptosporidium infections in sheep. This information will improve our knowledge and understanding of the epidemiology of cryptosporidiosis in China.IMPORTANCECryptosporidium is an important zoonotic parasite that causes diarrhea in humans and animals worldwide. Previous studies suggested geographic differences in the distribution of Cryptosporidium species in sheep. However, molecular characterization studies of Cryptosporidium species in sheep have been carried out in only a few provinces in China, and the limited data available do not reflect the real situation. In this study, five districts, covering most areas where sheep are bred in China, were selected for examination of Cryptosporidium species, and Cryptosporidium infections were detected at all farms assessed, suggesting that Cryptosporidium is widespread in sheep in China. We also found geographic differences in the distribution of Cryptosporidium species but did not detect any differences between sheep age groups or seasons. Subtyping analyses showed that all of the subtypes identified in this study have been reported in humans, suggesting that sheep may be a potential source of zoonotic cryptosporidiosis.

Synthesis of a Poly-l-Lysine/Black Phosphorus Hybrid for Biosensors.

A simple, noncovalent modification strategy was proposed to synthesize poly-l-lysine-black phosphorus (pLL-BP) hybrid. BP nanoflakes were prepared with a water-phase exfoliation method. pLL can adhere to the surface of BP via hydrophobic interaction between butyl chains of pLL and the BP surface as well as the electrostatic interaction between the protonated amino groups on pLL and the negative charge on deprotonated PxOy groups remaining on BP. The as-synthesized pLL-BP hybrid turns out to be an ideal matrix for hemoglobin immobilization and direct electron transfer. Good conductivity and biocompatibility of BP maintain the native structure and the bioactivity of hemoglobin (Hb), facilitating the direct electron transfer between the electroactive center of Hb and electrode. The rate constant ( kET) for direct electron transfer of Hb@pLL-BP is calculated to be 11.24 s-1. The constructed Hb-pLL-BP based enzymatic electrochemical biosensor displays excellent catalytic activity toward the reduction of oxygen and hydrogen peroxide. The electrochemical response toward H2O2 exhibits a linear dependence on hydrogen peroxide concentration ranging between 10 µM and 700 µM. The results demonstrate that the pLL-BP hybrid can act as a biocompatible building block for the construction of novel biofuel cells, bioelectronics, and biosensors.

[Study on the Analysis of the Proportion of Mixed Samples with Near Infrared Spectroscopy and Non-Negative Coefficients Regression].

In the process of practical production, it is important to accurately analyze the proportion of mixed samples with high speed, which plays a great role for quality control and formulation design in food and agricultural processing. Traditional solution is to build statistical model with a large number of representative samples, which is both labor-intensive and time-consuming. In this paper, the proportion of alcohol and acids mixed samples, and their dilute solution mixed samples(used carbon tetrachloride (CCl4) which has no near-infrared absorption characteristics as the solvent medium)，as well as sheet tobacco leaf mixed samples are respectively analyzed by using near infrared spectroscopy, SG smooth and non-negative coefficients regression, which verifies the feasibility of analyzing the proportion of the mixed samples. The results show that, the analytic proportion of transmission spectra of alcohol and acids according to non-negative coefficients regression is closer to actual molar proportion with result error less than 4%. The result of the dilute solution is much better with error less than 4%. The analytic proportion of diffuse reflectance spectra of sheet tobacco leaf according to non-negative coefficients regression is highly accurate with error less than 10%. In the meantime, it has a highly consistency between actual spectra and analytic spectra of mixed samples; and the result of F-test and T-test shows that there is no significant difference between them and the confidence level is 0.01. It has the reliability of analytical proportion in theory. With the spectral data of several pure samples, the proportion of mixed samples can be thus analyzed, which has a good application prospect for quality control and formulation design in food and agricultural processing.