[A phase I study of subcutaneous envafolimab (KN035) monotherapy in Chinese patients with advanced solid tumors]

Objective: To evaluate the safety and antitumor activity of envafolimab monotherapy in Chinese patients with advanced solid tumors. Methods: This open-label, multicenter phase I trial included dose escalation and dose expansion phases. In the dose escalation phase, patients received subcutaneous 0.1, 0.3, 1.0, 2.5, 5.0 or 10.0 mg/kg envafolimab once weekly (QW) following a modified "3+ 3" design. The dose expansion phase was performed in the 2.5 mg/kg and 5.0 mg/kg (QW) dose cohorts. Results: At November 25, 2019, a total of 287 patients received envafolimab treatment. During the dose escalation phase, no dose-limiting toxicities (DLT) was observed. In all dose cohorts, drug-related treatment-emergent adverse events (TEAEs) for all grades occurred in 75.3% of patients, and grade 3 or 4 occurred in 20.6% of patients. The incidence of immune-related adverse reactions (irAE) was 24.0% for all grades, the most common irAEs (≥2%) included hypothyroidism, hyperthyroidism, immune-associated hepatitis and rash. The incidence of injection site reactions was low (3.8%), all of which were grades 1-2. Among the 216 efficacy evaluable patients, the objective response rate (ORR) and disease control rate (DCR) were 11.6% and 43.1%, respectively. Median duration of response was 49.1 weeks (95% CI: 24.0, 49.3). Pharmacokinetic (PK) exposure to envafolimab is proportional to dose and median time to maximum plasma concentration is 72-120 hours based on the PK results from the dose escalation phase of the study. Conclusion: Subcutaneous envafolimab has a favorable safety and promising preliminary anti-tumor activity in Chinese patients with advanced solid tumors.

Exploring a high-urease activity Bacillus cereus for self-healing concrete via induced CaCO3 precipitation

The structural integrity and esthetic appeal of concrete can be compromised by concrete cracks. Promise has been shown by microbe-induced calcium carbonate precipitation (MICP) as a solution for concrete cracking, with a focus on urease-producing microorganisms in research. Bacillus cereus was isolated from soil and employed for this purpose in this study due to its high urease activity. The strain exhibited strong tolerance for alkaline media and high salt levels, which grew at a pH of 13 and 4% salt concentration. The repair of concrete cracks with this strain was evaluated by assessing the effects of four different thickeners at varying concentrations. The most effective results were achieved with 10 g/L of sodium carboxymethyl cellulose (CMC-Na). The data showed that over 90% repair of cracks was achieved by this system with an initial water penetration time of 30 s. The study also assessed the quantity and sizes of crystals generated during the bacterial mineralization process over time to improve our understanding of the process. KEY POINTS: • MICP using Bacillus cereus shows potential for repairing concrete cracks. • Strain tolerates alkaline media and high salt levels, growing at pH 13 and 4% salt concentration. • Sodium carboxymethyl cellulose (CMC-Na) at 10 g/L achieved over 90% repair of cracks.

IPTG-induced high protein expression for whole-cell biosynthesis of L-phosphinothricin

BACKGROUND

Biocatalytic production of L-phosphinothricin (L-PPT) is currently the most promising method. In this work, we use an Escherichia coli strain coexpressing of D-amino acid oxidase and catalase (E. coli DAAO-CAT) to oxidation biocatalytic D-PPT to PPO, then use the second E. coli strain coexpressing glutamate dehydrogenase and formate dehydrogenase (E. coli GluDH-FDH) to reduce biocatalytic PPO to L-PPT.

MAIN METHODS AND MAJOR RESULTS

We compared the effects of different concentrations of IPTG or lactose on protein expression and enzyme activity in 5 L fermenter. The best induction conditions for E. coli DAAO-CAT were 0.05 mM IPTG, induction for 18 h at 28°C. The specific enzyme activities of DAAO and CAT were 153.20 U g-1 and 896.23 U g-1 , respectively. The optimal induction conditions for E. coli GluDH-FDH were 0.2 mM IPTG, induction for 19 h at 28°C. The specific enzyme activities of GluDH and FDH were 41.72 U g-1 and 109.70 U g-1 , respectively. The 200 mM D-PPT was biocatalyzed by E. coli DAAO-CAT for 4 h with space-time yield of 9.0 g·L-1 ·h-1 and conversion rate of over 99.0%. Then 220 mM PPO was converted to L-PPT by E. coli GluDH-FDH for 3 h with space-time yield of 14.5 g·L-1 ·h-1 and conversion rate of over 99.0%. To our knowledge, this is the most efficient biocatalytic reaction for L-PPT production.

CONCLUSIONS AND IMPLICATIONS

We found that IPTG has advantages compared with lactose in the enzyme activity and biomass of E. coli DAAO-CAT and E. coli GluDH-FDH, and IPTG is more environmentally friendly. Our data implicated that IPTG can replace lactose in terms of economic feasibility and effectiveness for scaled-up industrial fermentations.

Unintrusive multi-cancer detection by circulating cell-free DNA methylation sequencing (THUNDER): development and independent validation studies

BACKGROUND

Early detection of cancer offers the opportunity to identify candidates when curative treatments are achievable. The THUNDER study (THe UNintrusive Detection of EaRly-stage cancers, NCT04820868) aimed to evaluate the performance of ELSA-seq, a previously described cfDNA methylation-based technology, in the early detection and localization of six types of cancers in the colorectum, esophagus, liver, lung, ovary and pancreas.

PATIENTS AND METHODS

A customized panel of 161,984 CpG sites was constructed and validated by public and in-house (cancer: n=249; non-cancer: n=288) methylome data, respectively. The cfDNA samples from 1,693 participants (cancer: n=735; non-cancer: n=958) were retrospectively collected to train and validate two multi-cancer detection blood test models (MCDBT-1/2) for different clinical scenarios. The models were validated on a prospective and independent cohort of age-matched 1,010 participants (cancer: n=505; non-cancer: n=505). Simulation using the cancer incidence in China was applied to infer stage-shift and survival benefits to demonstrate the potential utility of the models in the real world.

RESULTS

MCDBT-1 yielded a sensitivity of 69.1% (64.8%‒73.3%), a specificity of 98.9% (97.6%‒99.7%) and tissue origin accuracy of 83.2% (78.7%‒87.1%) in the independent validation set. For early stage (I‒III) patients, the sensitivity of MCDBT-1 was 59.8% (54.4%‒65.0%). In the real-world simulation, MCDBT-1 achieved the sensitivity of 70.6% in detecting the six cancers, thus decreasing late-stage incidence by 38.7%‒46.4%, and increasing 5-year survival rate by 33.1%‒40.4%, respectively. In parallel, MCDBT-2 was generated at a slightly low specificity of 95.1% (92.8%-96.9%) but a higher sensitivity of 75.1% (71.9%-79.8%) than MCDBT-1 for populations at relatively high risk of cancers, and also had ideal performance.

CONCLUSION

In this large-scale clinical validation study, MCDBT-1/2 models showed a high sensitivity, specificity, and accuracy of predicted origin in detecting six types of cancers.

[Roles of the CXCR1/CXCL8 axis in abnormal proliferation of bile duct epithelial cells in primary biliary cholangitis]

Objective: To investigate the role of the CXC chemokine receptor 1 (CXCR1)/CXC chemokine ligand 8 (CXCL8) axis in the abnormal proliferation of bile duct epithelial cells in primary biliary cholangitis (PBC). Methods: 30 female C57BL/6 mice were randomly divided into the PBC model group (PBC group), reparixin intervention group (Rep group), and blank control group (Con group) in an in vivo experiment. PBC animal models were established after 12 weeks of intraperitoneal injection of 2-octanoic acid coupled to bovine serum albumin (2OA-BSA) combined with polyinosinic acid polycytidylic acid (polyI:C). After successful modelling, reparixin was injected subcutaneously into the Rep group (2.5 mg · kg(-1) · d(-1), 3 weeks). Hematoxylin-eosin staining was used to detect histological changes in the liver. An immunohistochemical method was used to detect the expression of cytokeratin 19 (CK-19). Tumor necrosis factor-α (TNF-α), γ-interferon (IFN-γ) and interleukin (IL)-6 mRNA expression were detected by qRT-PCR. Western blot was used to detect nuclear transcription factor-κB p65 (NF-κB p65), extracellularly regulated protein kinase 1/2 (ERK1/2), phosphorylated extracellularly regulated protein kinase 1/2 (p-ERK1/2), Bcl-2-related X protein (Bax), B lymphoma-2 (Bcl-2), and cysteine proteinase-3 (Caspase- 3) expression. Human intrahepatic bile duct epithelial cells were divided into an IL-8 intervention group (IL-8 group), an IL-8+Reparicin intervention group (Rep group), and a blank control group (Con group) in an in vitro experiment. The IL-8 group was cultured with 10 ng/ml human recombinant IL-8 protein, and the Rep group was cultured with 10 ng/ml human recombinant IL-8 protein, followed by 100 nmol/L Reparicin. Cell proliferation was detected by the EdU method. The expression of TNF-α, IFN-γ and IL-6 was detected by an enzyme-linked immunosorbent assay. The expression of CXCR1 mRNA was detected by qRT-PCR. The expression of NF-κB p65, ERK1/2 and p-ERK1/2 was detected by western blot. A one-way ANOVA was used for comparisons between data sets. Results: The results of in vivo experiments revealed that the proliferation of cholangiocytes, the expression of NF-κB and ERK pathway-related proteins, and the expression of inflammatory cytokines were increased in the Con group compared with the PBC group. However, reparixin intervention reversed the aforementioned outcomes (P<0.05). In vitro experiments showed that the proliferation of human intrahepatic cholangiocyte epithelial cells, the expression of CXCR1 mRNA, the expression of NF-κB and ERK pathway-related proteins, and the expression of inflammatory cytokines were increased in the IL-8 group compared with the Con group. Compared with the IL-8 group, the proliferation of human intrahepatic cholangiocyte epithelial cells, NF-κB and ERK pathway-related proteins, and inflammatory indicators were significantly reduced in the Rep group (P < 0.05). Conclusion: The CXCR1/CXCL8 axis can regulate the abnormal proliferation of bile duct epithelial cells in PBC, and its mechanism of action may be related to NF-κB and ERK pathways.

A light-controlled biocatalytic system for precise regulation of enzymatic decarboxylation

A light-controlled biocatalytic one-pot system is developed, which enables precise regulation of gene expression and photocatalysis by illumination and yields high conversion and stereoselectivity.

Development of a fermentation strategy to enhance the catalytic efficiency of recombinant Escherichia coli for l-2-aminobutyric acid production

Microbial fermentation for enzyme production and then whole-cell catalysis for l-2-aminobutyric acid (l-ABA) production have huge potential for industrial application, but the catalytic capacities of cells are directly related to the fermentation process. Using a 50 L fermenter, the effects of initial glycerol concentration in the medium and rotating speed on cell catalytic capacity were investigated. Fermentation cells showed the best catalytic activity when the initial glycerol concentration was 12 g/L and the rotating speed was 250 rpm. Furthermore, we studied the difference between glycerol and glycerol mixtures as fed-batch media in pH-stat fed-batch fermentation. Results showed that glycerol had better catalytic activity than the glycerol mixture, and the effect of fed-batch fermentation was better than batch fermentation. Meanwhile, the enzyme activities of leucine dehydrogenase and formate dehydrogenase reached 129.87 U/g DCW and 437.02 U/g DCW, respectively, and the intracellular NAD(H) concentration reached 14.94 μmol/g DCW. Using the optimized fermentation parameters, amplified fermentation was then carried out in a 5000 L fermenter to demonstrate the industrial production of l-ABA by Escherichia coli BL21.

[The Chinese guidelines for the diagnosis and treatment of pancreatic neuroendocrine neoplasms (2020)]

Pancreatic neuroendocrine neoplasms (pNENs) are highly heterogeneous, and the management of pNENs patients can be intractable. To address this challenge, an expert committee was established on behalf of the Group of Pancreatic Surgery, Chinese Society of Surgery, Chinese Medical Association, which consisted of surgical oncologists, gastroenterologists, medical oncologists, endocrinologists, radiologists, pathologists, and nuclear medicine specialists. By reviewing the important issues regarding the diagnosis and treatment of pNENs, the committee concluded evidence-based statements and recommendations in this article, in order to further improve the management of pNENs patients in China.

[Analysis of clinical characteristics and prognosis of 235 pancreatic neuroendocrine tumors underwent Sunitinib treatment]

Objective: To investigate the clinical characteristics, treatment, and prognostic factors of pancreatic neuroendocrine tumors (pNETs) patients treated with Sunitinib. Methods: The clinical data of pNETs patients from Pfizer Drug Assistance Program of Cancer Foundation of China from April 2013 to November 2017 were retrospectively analyzed. Follow-up and statistical analysis were performed. Results: A total of 235 patients were enrolled, the patients' overall survival time was between 4 and 252 months, the 3-years and 5-years survival rates were 73.8% and 60.8%, respectively. Univariate analysis showed that factors such as age, Ki-67 index and surgery were associated with the 3-years survival rates of pNETs patients (P<0.05). Multivariate analysis demonstrated that the age, Ki-67 index and surgery were independent prognostic factors for pNETs patients (P<0.05). For patients with liver metastases, univariate analysis revealed that surgery was associated with prognosis (P<0.05). The 5-years survival rate of 124 patients with extending usage of Sunitinib was 53.3%. Conclusion: PNETs are rare tumors with atypical clinical symptoms and the patients often have metastasis at the initiate diagnosis. The age, Ki-67 index and surgery are associated with the prognosis of pNETs patients.

Development of a Combination Fermentation Strategy to Simultaneously Increase Biomass and Enzyme Activity of D-amino Acid Oxidase Expressed in Escherichia coli

D-amino acid oxidase (DAAO) is widely used in the industrial preparation of L-amino acids, and cultivating Escherichia coli (E. coli) expressing DAAO for the biosynthesis of L-phosphinothricin (L-PPT) is very attractive. At present, the biomass production of DAAO by fermentation is still limited in large-scale industrial applications because the expression of DAAO during the fermentation process inhibits the growth of host cells, which limits higher cell density. In this study, the factors that inhibit the growth of bacterial cells during a 5-L fed-batch fermentation process were explored, and the fermentation process was optimized by co-expressing catalase (CAT), by balancing the biomass and the enzyme activity, and by adding exogenous D-alanine (D-Ala) to relieve the limitation of DAAO on the cells and optimize fermentation. Under optimal conditions, the DO-STAT feeding mode with DO controlled at 30% ± 5% and the addition of 27.5 g/L lactose mixed with 2 g/L D-Ala during induction at 28 °C resulted in the production of 26.03 g dry cell weight (DCW)/L biomass and 390.0 U/g DCW specific activity of DAAO; an increase of 78% and 84%, respectively, compared with the initial fermentation conditions. The fermentation strategy was successfully scale-up to a 5000-L fermenter.

[Synchronous robotic resection for colorectal liver metastasis]

Surgical resection remains the only curative therapy for colorectal adenocarcinoma and liver metastasis. Synchronous robotic resection for colorectal liver metastasis (CRLM) offers the advantage of avoiding double surgical stress, while providing the benefits of small incision, quicker recovery, shorter hospital stay and faster postoperative adjuvant therapy. Compared with the laparoscopic approach, robotic approach is mostly suitable for rectal cancer liver metastasis, which is associated with low conversion rate, good nerve protection, high success rate for major hepatectomy and resection of difficult segments. Appropriately selected patients, multidisciplinary cooperation and skillful robotic surgeons are the key to success. Current data have demonstrated the feasibility and safety of synchronous robotic resection for CRLM. With the coming randomized controlled trial data and evolution of robotic surgical system, the future of synchronous robotic resection for colorectal liver metastasis is promising.

Luteoloside Ameliorates Palmitic Acid-Induced in Vitro Model of Non-alcoholic Fatty Liver Disease via Activating STAT3-Triggered Hepatocyte Regeneration

Luteoloside (Lute), a bioactive natural ingredient, widely exists in nature and possesses hepatoprotective and hepatocyte proliferation-promoting properties. This study aimed to investigate whether Lute could counteract non-alcoholic fatty liver disease (NAFLD)-caused hepatocyte damage via its stimulation of hepatocyte regeneration efficacy and to explore the involved mechanism. LO2 cells and primary hepatocytes were used to examine the hepatocyte proliferation effects of Lute under physiological conditions and in the palmitic acid (PA)- induced in vitro model of NAFLD. STAT3 and cell cycle-related proteins (cyclin D1, c-myc and p21) were evaluated by Western blot. Under physiological conditions, LO2 cells and primary hepatocytes treated with various concentration of Lute for 12 and 24 h showed increased hepatocyte proliferation, especially with 20 μM treatment for 24 h. More notably, under the model conditions, co-incubation with 20 μM of Lute also markedly reversed PA-induced inhibition of cell proliferation and viability in primary hepatocytes. Mechanistically, Lute could activate STAT3 and subsequently increase cyclin D1 and cmyc expression, which positively regulates cell cycle progression, and decrease expression of p21, an inhibitor of cell cycle progression. Furthermore, Luteinduced hepatocyte proliferation-promoting efficacy was abolished by STAT3 inhibitor stattic. Collectively, Lute can alleviate PA-induced hepatocyte damage via activating STAT3-mediated hepatocyte regeneration.

[Characteristics on molecular epidemiology of Brucella melitensis in Jiangxi province]

Objective: To understand the molecular characteristics and correlation among isolated strains of Brucella melitensis (BM) so as to improve the strategies on prevention and control of the disease in Jiangxi province. Methods: A total of 25 strains of BM isolated from human in 17 counties of Jiangxi province were analyzed by multiple locus variable-number tandem repeat analysis (MLVA) method. Results: A total of 25 strains of BM were classified into 24 independent genotypes with similarities between 67.00% and 100.00% and Simpson index between 0.000 and 0.773. There were 3 genotypes in MLVA8, including 60.00% (15/25) as 42 genotype, 32.00% (8/25) as 43 genotype, and 8.00% (2/25) as 63 genotype, respectively. There were 7 genotypes in MLVA11 identified, with 116 genotype and 125 genotype the main genotypes, accounting for 56.00% (14/25) of all the identified strains. Conclusions: Genes from all the 25 strains of BM that isolated from human being were with high genetic diversities, and various, genotypes. However, no obvious epidemiological correlation was noticed among these strains, indicating the complexity of the source of infection on Brucella in Jiangxi province.

[Experience of teaching and training for medical students at gastrointestinal surgery department under COVID-19 epidemic situation]

In hospitals and medical schools as densely populated sites with high risk of coronavirus disease 2019 (COVID-19), it is vital to adjust the teaching and training strategy for medical students to ensure curriculum completion with safety. This article aims to introduce the experience of teaching and training for medical students under the epidemic situation at Department of Surgery, Shanghai Medical College, Fudan University and Zhongshan Hospital. The content includes exploring diversified online teaching models for undergraduate surgery courses and clinical practice, carrying out online graduate education and dissertation plans, and strengthening comprehensive education of medical humanity combined with knowledge of COVID-19 prevention. Through implementation of the above teaching strategies, scheduled learning plans of medical students can be well completed in an orderly, safe and quality-ensured manner. Our experience provides practical solution of medical teaching and could be advisable for other medical colleges and teaching hospitals.

[Medical diagnosis and treatment strategies for malignant tumors of the digestive system during the outbreak of COVID-19]

Since the outbreak of COVID-19 in December 2019, the diagnosis and treatment of patients with cancer have been facing great challenges. Although oncologists are not fighting on the front line to against the epidemic, during this special period, we should not only protect patients, their families and medical staff from the infection of novel coronavirus, but also minimize the impact of the epidemic on the diagnosis and the treatment of patients with cancer. Combining the guidelines for diagnosis and treatment of tumors with our clinical experience, in this epidemic period, we discuss the strategies for diagnosis, treatment, and follow-up of malignant tumors of the digestive system in this article.

[Risk factors of anastomotic leakage after robotic surgery for low and mid rectal cancer]

Objective: To investigate the risk factors associated with anastomotic leakage after robotic surgery in mid-low rectal cancer. Methods: A retrospective case-control study method was conducted. Inclusion criteria: (1) 18 to 80 years old; (2) pathologically confirmed rectal cancer; (3) distance <10 cm from tumor to anal margin; (4) robotic anterior rectal resection. Patients with previous history of colorectal cancer surgery, distant metastases or other malignant tumors, undergoing emergency surgery, with severe abdominal adhesions or those receiving combined organ resection were excluded. Based on the above criteria, 636 patients undergoing robotic radical sphincter-preserving surgery for mid-low rectal cancer in Zhongshan Hospital from January 2015 to December 2018 were included in this study, including 398 males (62.6%) and 238 females (37.4%) with a mean age of (61.9±11.3) years. Sixty-eight cases (10.7%) received neoadjuvant chemoradiotherapy. Amony the 636 included patients, 123(19.3%) underwent natural orifice specimen extraction surgery (NOSES) and 15 (2.3%) underwent preventive stoma. According to the cirteria developed by the International Rectal Cancer Research Group in 2010, the anastomotic leakage was classified as grade A (no requirement of intervention), B (requirement of intervention), and C (requirement of operation). Logistic regression was used to analyze the relationship between anastomotic leakage and clinicopathological factors. Factors in univariate analysis with P<0.05 were included in the multivariate analysis. Results: Anastomotic leakage occurred in 38 cases (6.0%). The grading of anastomotic leakage was grade A in 13 cases (2.0%), grade B in 19 cases (3.0%), and grade C in 6 cases (0.9%). The 3-year disease-free survival rate of patients with anastomotic leakage and without anastomotic leakage was 83.5% and 83.6% respectively (P=0.862); the 3-year overall survival rate of the two group was 85.1% and 87.5% respectively (P=0.296). The results of univariate logistic regression analysis showed that male (P=0.011), longer operation time (P=0.042), distance ≤5 cm from tumor to anal margin (P=0.012), more intraoperative blood loss (P=0.048) were associated with anastomotic leakage (all P<0.05). NOSES was not associated with anastomotic leakage (P=0.704). Multivariate analysis confirmed that male (OR=3.03, 95%CI: 1.37 to 7.14, P=0.010), operation time ≥180 minutes (OR=2.04, 95%CI: 1.03 to 3.99, P=0.040), distance ≤5 cm from tumor to anal margin (OR=2.56, 95%CI:1.28 to 5.26, P=0.008) were independent risk factors for anastomotic leakage. Conclusion: Male, short distance from tumor to anal margin, and long operation time are independent risk factors for anastomotic leakage in patients undergoing robotic mid-low rectal cancer radical surgeries. These patients need to be cautiously treated during surgery.

[Current status and consideration of robotic surgery for colorectal cancer in China]

Since its inception, the surgical robot system with technical advantages has quickly become a new trend in surgery, and has been widely used at home and abroad. A large number of retrospective studies and a small number of randomized controlled studies have shown that compared with traditional laparoscopic surgery, robotic surgery presented some improvements, such as lower conversion rate, less urinary and sexual dysfunction, and less intraoperative blood loss, though more convincing evidence is needed. Robotic colorectal cancer surgery started late in China, but developed rapidly. Not only the number of surgeries has increased rapidly, but also many new surgeries have been innovated. Meanwhile, many problems emerged, such as lack of unified technical specifications, and excessive dependence on imported surgical robot equipment. Through high-quality clinical researches and big data analyses, the formulation of standardization, the establishment of training system, and the combination of medicine, research and production, robotic surgery will continue to lead the development trend of surgery in the new era.

Nanorectenna spectrally-selective plasmonic hot electron response to visible-light lasers

Active metasurfaces with novel visible and infrared (vis/IR) functionalities represent an exciting, growing area of research. Rectification of vis/IR frequencies would produce needed direct current (DC) with no inherent frequency limitation (e.g. no semiconducting bandgap). However, controlling the materials and functionality of (nano)rectennas for rectifying 100 s of THz to the visible regime is a daunting challenge, because of the small features and simultaneously the need to scale up to large sizes in a scalable platform. An active metasurface of a planar array of nanoscale antennas on top of rectifying vertical diodes is a 'nanorectenna array' or 'microrectenna array' that rectifies very high frequencies in the infrared, or even higher frequencies up to the visible regime. We employ a novel strategy for forming optical nanorectenna arrays using scalable patterning of Au nanowires, demonstrate strong evidence for spectral-selective high-frequency rectification, characteristic of optical antennas. We discover a previously unreported out-of-equilibrium electron energy distribution, i.e. hot electrons arising from plasmonic resonance absorption in an optical antenna characterized by an effective temperature, and how this effect can significantly impact the observed rectification.

Organic trace minerals improve eggshell quality by improving the eggshell ultrastructure of laying hens during the late laying period

The objective of this study was to investigate the effects of low inclusion levels of organic trace minerals (iron, copper, manganese, and zinc) on performance, eggshell quality, serum hormone levels, and enzyme activities of laying hens during the late laying period. A total of 405 healthy hens (HY-Line White, 50-week-old) were randomly divided into 3 treatments, with 9 replications per treatment and 15 birds per replication. The dietary treatments included a basal diet supplemented with inorganic trace minerals at commercial levels (CON), a basal diet supplemented with inorganic trace minerals at 1/3 commercial levels (ITM), and a basal diet supplemented with proteinated trace minerals at 1/3 commercial levels (TRT). The trial lasted 56 D (8 wk). Compared with the CON group, the ITM group showed decrease in (P < 0.05) egg production, eggshell strength, eggshell palisade layer, palisade layer ratio, serum estrogen, luteinizing hormone, glycosaminoglycan concentration, and carbonic anhydrase activity and increase in (P < 0.05) egg loss and mammillary layer ratio. However, the TRT group almost kept all the indices close to the CON group (P > 0.05). Furthermore, hens fed with low inclusion levels of organic trace minerals had smaller mammillary knobs (P < 0.05) than those in the CON and ITM groups. In conclusion, hens fed with low inclusion levels of proteinated trace minerals had better performance and eggshell strength than those fed with identical levels of inorganic compounds; organic trace minerals improved eggshell quality by improving the eggshell ultrastructure of laying hens during the late laying period.

Quasiparticle Screening near a Bosonic Superconductor-Insulator Transition Revealed by Magnetic Impurity Doping

Experiments show that the Cooper pair transport in the insulator phase that forms at thin film superconductor to insulator transitions (SIT) is simply activated. The activation energy T_{0} depends on the microscopic factors that drive Cooper pair localization. To test proposed models, we investigated how a perturbation that weakens Cooper pair binding, magnetic impurity doping, and phase frustration affects T_{0}. The data show that T_{0} decreases monotonically with doping in films tuned farther from the SIT and increases and peaks in films that are closer to the SIT critical point. The observations provide strong evidence that the bosonic SIT in thin films is a Mott transition driven by Coulomb interactions that are screened by virtual quasiparticle excitations. This dependence on underlying fermionic degrees of freedom distinguishes these SITs from those in microfabricated Josephson Junction arrays, cold atom systems, and likely in high temperature superconductors with nodes in their quasiparticle density of states.

Fermentative production of the unnatural amino acid L-2-aminobutyric acid based on metabolic engineering

Background

l-2-aminobutyric acid (l-ABA) is an unnatural amino acid that is a key intermediate for the synthesis of several important pharmaceuticals. To make the biosynthesis of l-ABA environmental friendly and more suitable for the industrial-scale production. We expand the nature metabolic network of Escherichia coli using metabolic engineering approach for the production of l-ABA.

Results

In this study, Escherichia coli THR strain with a modified pathway for threonine-hyperproduction was engineered via deletion of the rhtA gene from the chromosome. To redirect carbon flux from 2-ketobutyrate (2-KB) to l-ABA, the ilvIH gene was deleted to block the l-isoleucine pathway. Furthermore, the ilvA gene from Escherichia coli W3110 and the leuDH gene from Thermoactinomyces intermedius were amplified and co-overexpressed. The promoter was altered to regulate the expression strength of ilvA* and leuDH. The final engineered strain E. coli THR ΔrhtAΔilvIH/Gap-ilvA*-Pbs-leuDH was able to produce 9.33 g/L of l-ABA with a yield of 0.19 g/L/h by fed-batch fermentation in a 5 L bioreactor.

Conclusions

This novel metabolically tailored strain offers a promising approach to fulfill industrial requirements for production of l-ABA.

Electronic supplementary material

The online version of this article (10.1186/s12934-019-1095-z) contains supplementary material, which is available to authorized users.

[Prognostic analysis of colon and rectal neuroendocrine neoplasm in different stages]

Objective: To explore the survival difference of patients with colon and rectal neuroendocrine neoplasm (NEN) at different stages. Methods: We identified 8 679 patients with colorectal NEN diagnosed between 1988 and 2014 from the Surveillance, Epidemiology, and End Results (SEER) registry, including 5 437 rectal NEN and 3 242 colon NEN ( 1 681 cecum NEN ). Survival curve was drawn by Kaplan-Meier method. Prognostic factors were analyzed by univariate analysis and multivariate Cox regression model. Results: The ratio of male patients with colon and rectal NEN was similar to female (P=0.095). Rectal NEN patients were younger (P<0.001), more highly differentiated (P<0.001), and with earlier stage (P<0.001). Survival analysis showed that the survival of rectal NEN was superior to that of colon NEN, with 10-year tumor-specific survival rates of 86.8% and 44.8% respectively (P<0.001). Multivariate Cox analysis showed that age, gender, marital status, primary tumor site, grade, stage and surgery were independent prognostic factors of colorectal NEN (all P<0.01). The most important factor was stage (HR=3.531), followed by differentiation grade (HR=1.856). Stratified analysis displayed that the survival of rectal NEN in stage Ⅰ, Ⅱ and Ⅳ were better than those of corresponding stage of colon NEN (all P<0.05), but worse in stage Ⅲ (P=0.012). While the survival of rectal NEN were significantly better than those of colon NEN within all stages after excluding 1681 cases of cecal NEN (all P<0.05). Among the patients with well-differentiated NEN, the survival of rectal NEN in stage Ⅰ, Ⅲ and Ⅳ were better than those of corresponding stage of colon NEN (all P<0.05) while there was no significant difference in stage Ⅱ(P=0.169). For poor-differentiated NEN, only the survival of rectal NEN patients in stage Ⅳ (P=0.001) was significant longer than those of colon NEN, while there was no significant difference in stage Ⅰ, Ⅱ and Ⅲ (stage Ⅰ: P=0.760; stage Ⅱ: P=0.181; stage Ⅲ: P=0.313). Conclusions: The survival of NEN patients in colon and rectum is different. Cecum NEN should be considered as a separated tumor for prognostic analysis due to its special clinicopathologic characteristics.

[Current treatment in advanced hepatocellular carcinoma and prospects for immuno-oncology therapy]

Treatment of patients with advanced hepatocellular carcinoma (HCC) remains a huge challenge since a widely accepted therapeutic strategy has not been identified. There are some special features in patients with HCC in China, such as are mainly related to hepatitis B virus infection, often diagnosed as advanced or end-stage disease, and usually have a poorer prognosis compared with patients in western countries. Hence, appropriate treatments are urgently needed for these patients. Notably, immune-oncology therapy has been received increased attention in recent years. Based on promising results observed in clinical trials, immune-oncology therapy has been approved for treatment of various malignant diseases and brings a new hope to the treatment of advanced HCC. The review summarizes the current situation of advanced HCC treatment in China and discusses the prospects of immuno-oncology therapy.

[The value of MRI in early diagnosis of dysbaric osteonecrosis]

Objective: To investigate the value of MRI in the early diagnosis of diagnosis of dysbaric osteonecrosis. Methods: Labor hygiene investigation and occupation health were examined on 52 high pressure operating personnel, were selected for the examination of both shoulders, hips and knees with X-ray and CT scan. Results: The cystic sign in dysbaric osteonecrosis as an important imaging feature, which perform in the MRI examination for T1W I sequence showed low or slightly low signal and T2W I sequence showed high signal, and X-ray and CT have a lower detection rate than MRI. The Kappa consistency test showed a high consistency with the two methods. At the same time MRI examination also can discover the bone marrow cavity necrosis early pathological change. Conclusion: MRI is an effective method for the diagnosis of early dysbaric osteonecrosis, which can improve the early diagnosis rate of dysbaric osteonecrosis.

[A 3.0 T MRI study on the alterations of the volume and morphology of fifteen subcortical nucleus in patients with early post-stroke depression]

Objective: To investigate the alterations of the volumes and 3D shapes of fifteen subcortical nucleus in patients with post-stroke depression (PSD) and to explore the pathogenesis regularity and mechanism of early PSD. Methods: From 2015 to 2017, a total of 28 patients with PSD and 18 stroke patients without depression (PSND), 13 patients with depression (De) and 11 cases of healthy volunteers (NC) were enrolled to perform 3.0 T high resolution MRI.Computer automatic segmentation and vertex analysis were used to segment and measure the volume of bilateral nucleus accumbens, caudate nucleus, putamen, globus pallidus, thalamus, hippocampus, mygdale and brainstem. Results: The volume of bilateral nucleus accumbens and bilateral thalamus, left pallidum were different among groups with statistical difference (P<0.05). The nucleus volume of the PSD group was (415±128) mm(3) (L-Nac)/(303±90) mm(3) (R-Nac), (7 590±867) mm(3) (L-Th)/(7 459±905) mm(3) (R-Th), (1 675±328) mm(3) (L-Pa), which was smaller than that of PSND group (433±100) mm(3) /(307±88) mm(3), (7 999±961) mm(3) /(7 753± 955) mm(3), (1 790±286) mm(3) and other groups.The nuclei with significantly statistical differences between inter-group were found in following: between PSD group and NC group, right accumbens and bilateral thalamus (P<0.01); between PSD group and De group, right accumbens and right thalamus (P<0.001), left accumbens, left pallidum and left thalamus (P<0.01); between PSND group and NC group, right accumbens (P<0.05); between PSND group and De group, right accumbens (P<0.001), left accumbens and right thalamus (P<0.05). Significant differences in morphology changes of nuclei (P<0.05) by F test mainly located on the top and tail of right accumbens, the anterior and middle body of right caudate nucleus, the most part of bilateral thalamus, the ventromedial body of bilateral hippocampus, the anterior and body of left caudate nucleus, especially in left thalamus. Conclusion: PSD has abnormal volume and morphological structure of subcortical nuclei, which supports the role of subcortical structures changes in the pathophysiology and pathogenesis of early PSD.

Significant improvement of the nitrilase activity by semi-rational protein engineering and its application in the production of iminodiacetic acid

Iminodiacetic acid (IDA) is widely used as an intermediate in the manufacturing of chelating agents, glyphosate herbicides and surfactants. To improve activity and tolerance to the substrate for IDA production, Acidovorax facilis nitrilase was selected for further modification by the gene site saturation mutagenesis method. After screened by a two-step screening method, the best mutant (Mut-F168V/T201N/S192F/M191T/F192S) was selected. Compared to the wild-type nitrilase, Mut-F168V/T201N/S192F/M191T/F192S showed 136% improvement in specific activity. Co²⁺ stimulated nitrilase activity, whereas Cu²⁺, Zn²⁺ and Tween 80 showed a strong inhibitory effect. The V_max and k_cat of Mut-F168V/T201N/S192F/M191T/F192S were enhanced 1.23 and 1.23-fold, while the K_m was decreased 1.53-fold. The yield of Mut-F168V/T201N/S192F/M191T/F192S with 453.2 mM of IDA reached 71.9% in 5 h when 630 mM iminodiacetonitrile was used as substrate. This study indicated that mutant nitrilase obtained in this study is promising in applications for the upscale production of IDAN.

[Circulating tumor DNA and targeted therapy in colorectal cancer]

The detection of circulating tumor DNA is a quick, low cost and reliable approach of liquid biopsy of cancer. It has a wide range of applications for tumor screening because of its noninvasive, convenient and highly repeatable features. In terms of the targeted therapy in patients with colorectal cancer, serial monitoring of circulating tumor DNA, especially for the specific genetic alterations, can be used for prognosis, monitoring resistance, evaluation of therapeutic effects and screening combined targeted therapy. Therefore, it will guide more precise treatment of colorectal cancer.

[Surgical treatment of colorectal liver metastases]

Surgical resection of the metastases offers the only opportunity for long-term survival in colorectal liver metastases. However, only 10% to 20% of patients present with resectable disease, and so how to increase surgical patients has been a clinical hotspot. In addition to expanding surgical indications, two-stage hepatectomy and convertible therapy are optional. In convertible therapy, initial treatment regimen decides long-term benefit, and it is important to select appropriate patient population in addition to Ras status when anti-epithelial growth factor receptor monoclonal antibody is used. Minimally invasive surgery can also be used for liver resection and simultaneous resection, and it is safe and effective. For patients with colorectal cancer and unresectable asymptomatic liver metastases, the debate continues over the efficacy of primary resection compared to chemotherapy alone, limited by lack of prospective evidence. Therefore, multidisciplinary team assessment is essential to optimize outcomes in colorectal liver metastases.

The effects of neighborhood views containing multiple environmental features on road traffic noise perception at dwellings

The importance of non-acoustical factors including the type of visual environment on human noise perception becomes increasingly recognized. In order to reveal the relationships between long-term noise annoyance and different types of neighborhood views, 2033 questionnaire responses were collected for studying the effect of perceptions of different combinations of views of sea, urban river, greenery, and/or noise barrier on the annoyance responses from residents living in high-rise apartments in Hong Kong. The collected responses were employed to formulate a multivariate model to predict the probability of invoking a high annoyance response from residents. Results showed that views of sea, urban river, or greenery could lower the probability, while views of noise barrier could increase the probability. Views of greenery had a stronger noise moderation capability than views of sea or urban river. The presence of an interaction effect between views of water and views of noise barrier exerted a negative influence on the noise annoyance moderation capability. The probability due to exposure to an environment containing views of noise barriers and urban rivers would be even higher than that due to exposure to an environment containing views of noise barriers alone.

Evaporating metal nanocrystal arrays

Anodic aluminum oxide (AAO) substrates with a self-ordered triangular array of nanopores provide the means to fabricate multiple forms of nano materials, such as nanowires and nanoparticles. This study focuses on nanostructures that emerge in thin films of metals thermally evaporated onto the surface of AAO. Previous work showed that films of different evaporated metals assume dramatically different structures, e.g. an ordered triangular array of nearly monodisperse nanoparticles forms for lead (Pb) while a polycrystalline nanohoneycomb structure forms for silver (Ag). Here, we present investigations of the effects of substrate temperature and deposition angle that reveal the processes controlling the nano particle array formation. Our findings indicate that arrays form provided the grain nucleation density exceeds the pore density and the atomic mobility is high enough to promote grain coalescence. They introduce a method for producing films with anisotropic grain array structure. The results provide insight into the influence of substrate nano-morphology on thin film growth energetics and kinetics that can be harnessed for creating films with other novel nano-structures.

Driving a Superconductor to Insulator Transition with Random Gauge Fields

Typically the disorder that alters the interference of particle waves to produce Anderson localization is potential scattering from randomly placed impurities. Here we show that disorder in the form of random gauge fields that act directly on particle phases can also drive localization. We present evidence of a superfluid bose glass to insulator transition at a critical level of this gauge field disorder in a nano-patterned array of amorphous Bi islands. This transition shows signs of metallic transport near the critical point characterized by a resistance , indicative of a quantum phase transition. The critical disorder depends on interisland coupling in agreement with recent Quantum Monte Carlo simulations. We discuss how this disorder tuned SIT differs from the common frustration tuned SIT that also occurs in magnetic fields. Its discovery enables new high fidelity comparisons between theoretical and experimental studies of disorder effects on quantum critical systems.

Association between the AGTR1 A1166C polymorphism and risk of IgA nephropathy: a meta-analysis

Numerous studies have evaluated the association between the A1166C polymorphism in the angiotensin II type 1 receptor (AGTR1) gene and immunoglobulin A nephropathy (IgAN) risk. However, this relationship remains controversial. Our aim was to evaluate the relationship between this polymorphism and IgAN susceptibility by performing a meta-analysis. Articles were identified in the PubMed, Google Scholar, and China National Knowledge Infrastructure databases, and after selection, five eligible studies were included. Statistical analyses were carried out using Stata 12.0, combining data from all the relevant studies. The pooled odds ratios (ORs) regarding the association between the AGTR1 A1166C polymorphism and IgAN risk were not statistically significant [A vs C: OR = 0.64, 95% confidence interval (CI) = 0.24-1.68; AA vs AC+CC: OR = 1.02, 95%CI = 0.74-1.39; CC vs AC+AA: OR = 1.20, 95%CI = 0.48-2.98; AC vs AA+CC: OR = 0.96, 95%CI = 0.70-1.31]. In conclusion, the AGTR1 gene A1166C polymorphism may not be correlated with IgAN susceptibility. However, further studies should be performed to confirm this finding.

Ultrasound Findings of Intraductal Papillary Neoplasm in Bile Duct and the Added Value of Contrast-Enhanced Ultrasound

PURPOSE

To investigate the imaging features of intraductal papillary neoplasm in bile duct (IPNB) on baseline ultrasound and contrast-enhanced ultrasound (CEUS).

MATERIALS AND METHODS

The imaging features on baseline ultrasound and CEUS in 16 pathologically proven IPNB lesions in 15 patients were retrospectively analyzed. Real-time contrast specific modes and contrast agent of SonoVue were used for CEUS.

RESULTS

Bile duct dilation was present in all patients. The mean lengths for the intraductal papillary adenomas and adenocarcinomas were 2.5 ± 1.1 (range, 1.2 - 4.2 cm) and 5.6 ± 2.0 cm (range, 3.3 - 9.8 cm) (P = 0.004). Three imaging types of IPNB on ultrasound were depicted: bile duct dilation with intraductal mass (n = 8), bile duct dilation without intraductal mass (n = 3), and cystic-solid mixed type (n = 5). On CEUS, solid components of 13 lesions appeared hyper- (n = 12) or iso-enhancement (n = 1) in the arterial phase whereas all showed hypo-enhancement in the portal and late phases. For 3 lesions of bile duct dilation without intraductal mass, CEUS showed non-enhancement during all phases. Pre-surgical CEUS and conventional ultrasound made correct diagnoses in 12 (75.0 %) and 5(31.3 %) of 16 IPNBs respectively (P = 0.04). For CECT, correct diagnosis was also achieved in 12 (75.0 %) of 16 lesions (P = 1.00, in comparison with CEUS).

CONCLUSIONS

IPNB should be taken into consideration when intraductal mass or cystic-solid mass with bile duct dilation, or remarkable bile duct dilation without intraductal mass, are found on US. Intraductal mass length > 3.0 cm is more commonly found in malignant IPNB. CEUS might facilitate the diagnosis of IPNB by easily excluding the possibility of commonly found sludge, nonshadowing stones, or blood clots.

Improvement and characterization of a hyperthermophilic glucose isomerase from Thermoanaerobacter ethanolicus and its application in production of high fructose corn syrup

High fructose corn syrup (HFCS) is an alternative of liquid sweetener to sucrose that is isomerized by commercial glucose isomerase (GI). One-step production of 55 % HFCS by thermostable GI has been drawn more and more attentions. In this study, a new hyperthermophilic GI from Thermoanaerobacter ethanolicus CCSD1 (TEGI) was identified by genome mining, and then a 1317 bp fragment encoding the TEGI was synthesized and expressed in Escherichia coli BL21(DE3). To improve the activity of TEGI, two amino acid residues, Trp139 and Val186, around the active site and substrate-binding pocket based on the structural analysis and molecular docking were selected for site-directed mutagenesis. The specific activity of mutant TEGI-W139F/V186T was 2.3-fold and the value of k  cat/K  m was 1.86-fold as compared to the wild type TEGI, respectively. Thermostability of mutant TEGI-W139F/V186T at 90 °C for 24 h showed 1.21-fold extension than that of wild type TEGI. During the isomerization of glucose to fructose, the yield of fructose could maintain above 55.4 % by mutant TEGI-W139F/V186T as compared to 53.8 % by wild type TEGI at 90 °C. This study paved foundation for the production of 55 % HFCS using the thermostable TEGI.

Blockade of the CXCR6 signaling inhibits growth and invasion of hepatocellular carcinoma cells through inhibition of the VEGF expression

Chemokines have been shown to play a critical role in tumor development and progression. However, little is known about the function and molecular mechanisms of CXCR6 in multiple malignancies. In the present study, we aimed to investigate the role of CXCR6 in human hepatocellular carcinoma (HCC). The expression of CXCR6 was examined by immunohistochemical assay using a tissue microarray procedure. A loss-of-function experiment was performed to explore the effects of lentivirus-mediated CXCR6 shRNA (shCXCR6) on cell proliferation and invasive potential by MTT and Transwell assays in HCC cell line (SMMC-7721). It was found that the expression of CXCR6 protein was significantly increased in HCC tissues compared with that in adjacent non-cancerous tissues (ANCT) (63.04&#x0025; vs 36.96&#x0025;, P=0.019), and correlated with the lymph-vascular space invasion in HCC patients (P=0.038). Knockdown of CXCR6 repressed cell proliferation and invasion of HCC cells followed by the down-regulation of vascular endothelial growth factor (VEGF). Taken together, our findings show that high expression of CXCR6 is positively associated with distant invasion of HCC patients, and blockade of CXCR6 signaling suppresses the growth and invasion of HCC cells through inhibition of the VEGF expression, suggesting that CXCR6 may represent a promising therapeutic target for the treatment of HCC.

A study on dysbaric osteonecrosis in caisson workers

PURPOSE

To study the effects of exposure to compressed air on tunnel workers' health and to investigate the prevalence of dysbaric osteonecrosis (DON) in caisson workers.

METHODS

128 tunnel workers were divided into the exposed group (n = 58) and the control group (n = 70), and their shoulders, hips and knees were examined with X-ray, computed tomography (CT) and magnetic resonance imaging (MRI).

RESULTS

1) 34.5% of the exposed group were diagnosed with DON based on the national diagnostic criteria of decompression sickness. 2) The incidental difference of skeletal cystic changes between the exposed group and the control group was highly statistically significant (p < 0.01). 3) CT and MRI examination could detect early onset of DON lesions, and the cystic changes shown in CT and abnormal signals in MRI were diagnostic indicators in cases.

CONCLUSION

Cystic changes in CT and abnormal signals in MRI are key imaging findings of early DON.

Ag-decorated TiO₂ nanograss for 3D SERS-active substrate with visible light self-cleaning and reactivation

The production of SERS-active substrates which are uniform, sensitive, reproducibile and durable still remains an important issue. Here, we report a strategy for the fabrication of a large-area Ag-decorated TiO₂ nanograss SERS-active substrate by a simple solvothermal approach combined with Ag evaporation. The nanograss consists of dense rutile TiO₂ nanorods of about 5 nm in diameter and the decorated Ag nanoparticles are an average of 8 nm in diameter. The Ag protrusions and gaps between them contribute to three dimensional SERS "hot spots" which can be modulated by simply controlling the Ag evaporating parameters. The Ag-decorated TiO₂ substrate is highly efficient in detecting rhodamine 6G (R6G) and 4-aminothiophenol (4-ATP) molecules and has good homogeneity. An obvious red shift and even high enhancement of b₂ vibration mode were observed in detecting 4-ATP due to the effective charge transfer from the Ag atoms to sulfur atoms. The Ag-decorated TiO₂ substrate can be easily self-cleaned and reactivated by visible light irradiation without obvious degeneration of SERS signals. Our results demonstrate that the Ag-decorated TiO₂ substrate with high and homogeneous SERS activity has potential feasibility as a sensitive SERS probe.

Observation of giant positive magnetoresistance in a Cooper pair insulator

Ultrathin amorphous Bi films, patterned with a nanohoneycomb array of holes, can exhibit an insulating phase with transport dominated by the incoherent motion of Cooper pairs (CP) of electrons between localized states. Here, we show that the magnetoresistance (MR) of this Cooper pair insulator (CPI) phase is positive and grows exponentially with decreasing temperature T, for T well below the pair formation temperature. It peaks at a field estimated to be sufficient to break the pairs and then decreases monotonically into a regime in which the film resistance assumes the T dependence appropriate for weakly localized single electron transport. We discuss how these results support proposals that the large MR peaks in other unpatterned, ultrathin film systems disclose a CPI phase and provide new insight into the CP localization.

Heritability of metabolic syndrome traits among healthy younger adults: a population based study in China

OBJECTIVE To estimate heritability of metabolic syndrome traits among healthy younger adults in a human population in China, and examine potential sex differences in heritability and parental effect on metabolic syndrome traits. METHODS Using offspring-parent regression, we estimated heritability (h(2)) of metabolic syndrome traits based on 452 child-parent triads identified from a population based random survey on metabolic syndrome among people over 15 years of age in Guangzhou, China. RESULTS Body mass index (BMI), cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), fasting plasma glucose (FPG) and waist circumference (waist-C) were more heritable (h(2), 0.42-0.545), whereas systolic blood pressure (SBP), diastolic blood pressure (DBP), and triglycerides (TG) were less heritable (h(2), 0.14-0.28). Sons had pronounced increases in heritability for all traits over daughters, particularly for cholesterol (0.653 vs 0.356), FPG (0.602 vs 0.313), LDL-C (0.521 vs 0.329), and TG (0.395 vs 0.187). Offspring-mother seemed to have a higher heritability in every trait except FPG (0.67 vs 0.794) than offspring-father, most notably for DBP (0.308 vs 0.122), SBP (0.288 vs 0.146), TG (0.387 vs 0.239) and waist-C (0.581 vs 0.354). CONCLUSION We estimated the heritability of metabolic syndrome traits in a human population based on a unique population based offspring-parent sample from China, and found important evidence that the maternal and paternal effects on these traits are different and the sex difference in heritability is pronounced.

Kinetic distribution of 14C-metsulfuron-methyl residues in paddy soils under different moisture conditions

Rice paddy soils undergo several cycles of drying and wetting during a growing season. A laboratory study was conducted to determine the effect of soil moisture conditions on the distribution and kinetics of extractable and bound residues of 14C-metsulfuron-methyl in six Chinese paddy soils during 84 d of incubation at 15 degrees C with moisture contents varying from 20 to 50% of the field water-holding capacity. The amount of extractable residues consistently increased and bound residues decreased with increasing soil moisture content. At the end of the incubation experiments, extractable residues and bound residues accounted for 34.5 to 84.4% and 11.6 to 53.3% of applied radioactivity in soils, respectively. Soil pH and soil microbial biomass carbon were the most predominant factors affecting the formation and relative distribution of herbicide residues between extractable and bound residue forms. In high-pH soils, bound residues decreased and extractable residues increased, suggesting an increased leaching risk for metsulfuron-methyl in alkaline soils. High precipitation rates, along with the common practice of liming in southeastern China, may lead to enhanced herbicide leaching as well as phytotoxicity to rotation plants and should be considered in overall pest management practices.

Improvement of amidase production by a newly isolated Delftia tsuruhatensis ZJB-05174 through optimization of culture medium

The R-amidase production by a newly isolated strain of Delftia tsuruhatensis ZJB-05174 was optimized in this paper. Effects of factors such as carbon sources, nitrogen sources, and inducers on amidase production were investigated. The medium composition was optimized using central composite designs and response surface analysis. The optimal medium components for enhanced amidase production were found to be as follows: glucose, 8.23 g/l; yeast extract, 11.59 g/l; 2,2-(R,S)-dimethylcyclopropane carboxamide, 1.76 g/l; NaCl, 1 g/l; KH2PO4, 1 g/l; and K2HPO4, 1 g/l. A maximum enzyme production of 528.21 U/l was obtained under the optimized conditions, which was 4.7 times higher than that obtained under initial conditions.