岩土工程基坑支护工程中常见的问题及对策

对于岩土工程而言,保障工程的稳定性和安全性是最为重要的,这就要求工程负责人一定要打好地基,为工程奠定扎实的基础。理所当然,基抗支护工程的建设成了岩土工程施工中最关键的部分。因此,工程负责人应充分重视对基抗支护工程的施工,保障岩土工程最终的品质和质量,提高施工效率,提升安全性。文章针对岩土工程基抗支护工程中常见的问题及对策展开讨论和分析,以供参考。

Plant biotechnology:a case study of Bacillus thuringiensis(Bt) and its application to the future of genetic engineered trees

Agricultural productivity may be raised in a sustainable way by many different technologies such as biological fertilizers, soil and water conservation, biodiversity conservation, improved pest control, and changes in land ownership and distribution. Of these measures, biotechnology applications probably hold the most promise in augmenting conventional agricultural productivity, because biotechnology applications give not only the need to increase production, but also protect the environment and conserving natural resources for future generations. Biotechnology applications will have the possibilities to increase productivity and food availability through better agronomic performance of new varieties, including resistance to pests; rapid multiplication of disease-free plants; ability to obtain natural plant products using tissue culture; diagnosis of diseases of plants and livestock; manipulation of reproduction methods increasing the efficiency of breeding; and the provision of incentives for greater participation by the private sector through investments. Insect resistance through the transfer of a gene for resistance fromBacillus thuringiensis (Bt) is one of the most advanced biotechnology applications already being commercialized in many parts of the world. This paper reviews the development and the status ofBt technology and application ofBt transgenic plants in current agriculture, and discusses specific issues related to the transfer of the technology to the future of genetic engineered trees with emphasis on conifers. Key words Agricultural productivity - Bacillus thuringiensis - Genetic engineering - Insect resistance - Trees CLC number Q812 - S763.306 Document code A Biography: Tang Wei (1964-), male, Ph. Doctor, Research associate, Department of Biology, Howell Science Complex, East Carelina University, Greenville, NC 27858-4353, USA.Responsible editor: Chal Ruihai

Cloning and Efficient Expression of Bacillus sp. BH072 tas A Gene in Escherichia coli

The Bacillus strain BH072 isolated from a honey sample showed strong antifungal activity against phytopathogen. Gene cloning test demonstrated that the strain had a tasA gene encoding an antifungal TasA protein. Although the wild strain simultaneously produced various antifungal substances, only the physicochemical property and antifungal activity of TasA protein were unclear due to the difficulty in extraction. In this study, tasA gene encoding the protein from Bacillus sp. BH072 was amplified by using the polymerase chain reaction （PCR） method and cloned into pET 28a （＋） vector, and then expressed in host cells Escherichia coli BL21 （DE3）. The expressed proteins were collected by centrifugation and ultrasonic treatment, and then purified by using nickel-nitrilotriacetic acid （Ni-NTA） metal affinity column and dialysis methods. The result of sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE） test showed that an expected protein band appeared with a size of 31 kDa. The expressed products possessed antifungal activity against the phytopathogenic indicator strain Botrytis cinerea. A genetically engineered strain tasA orE, coli was established in this study which can efficiently express Tas A protein.

Spotlight on chimeric antigen receptor engineered T cell research and clinical trials in China

T cell mediated adoptive immune response has been characterized as the key to anti-tumor immunity. Scientists around the world including in China, have been trying to harness the power of T cells against tumors for decades. Recently, the biosynthetic chimeric antigen receptor engineered T cell(CAR-T) strategy was developed and exhibited encouraging clinical efficacy, especially in hematological malignancies. Chimeric antigen receptor research reports began in 2009 in China according to our Pub Med search results. Clinical trials have been ongoing in China since 2013 according to the trial registrations on clinicaltrials.gov.. After years of assiduous efforts, research and clinical scientists in China have made their own achievements in the CAR-T therapy field. In this review, we aim to highlight CAR-T research and clinical trials in China, to provide an informative reference for colleagues in the field.

Logic-signal output of fluorescent proteins for screening antibiotic combinations

A new method to screen antibiotic combinations is demonstrated,which takes advantage of the logic-signal output of genetically engineered drug-resistant E.coli strains expressing different fluorescent proteins.Thirty-six antibiotic combinations for nine antibiotics were investigated.The operation of different logic gates can reveal the susceptibility,resistance,or synergistic effect of the antibiotic combinations in a rapid(7–8 h versus 24–28 h for typical growth-based assays),simple,quantitative and high-throughput manner.This logic-signal-based output patterns provide the basis for novel and reliable screening of antibiotic combinations and help us to both gain insight into the mechanisms of multi-drug action.

Armed T cells with CAR for cancer immunotherapy

The development of genetic engineering has enabled the modification of stem cells and somatic cells.T cells exert immune responses against cancer cells.Efforts to redirect T cell specificity of a chimeric antigen receptor(CAR)to a desired antigen began in the 1990s(Gross et al.,1989;Kuwana et al.,1987).In 2006,the first clinical trial using carbonic anhydrase IX CAR-T cells to fight renal cancer was conducted(Lamers et al.,2006).Until 2011,Porter et al.exploited CD19 CAR-T to treat refractory/relapsed chronic lymphoid leukemia(Porter et al.,2011).Subsequently。