Advances in Natural Killer Cells and Immunotherapy for Gastric Cancer

Gastric cancer is one of the common malignant tumors in the gastrointestinal tract, and the treatment of gastric cancer includes the main ways such as radical resection, adjuvant chemotherapy, palliative care, and drug therapy; however, patients often have defects such as high recurrence rate, high treatment burden, and serious side effects, which impose a heavy burden on the economic and social construction and patients’ families. In recent years, novel gastric cancer treatment methods featuring tumor immunotherapy have provided new treatment strategies to improve the above-mentioned defects and increase the cure rate of patients. Natural killer cells (NK cells) are key components of the body’s intrinsic immune response and can participate in both the intrinsic and adaptive immune responses, exercising the functions of tumor killing, removing pathogenic microorganisms or abnormal cells and enhancing immunity, and thus have broad prospects for new drug development and clinical treatment. This article reviews the biological properties and functions of NK cells and their interrelationship with gastric cancer treatment, and provides a reference for clinical research

Biodegradable Polydepsipeptides

This paper reviews the synthesis, characterization, biodegradation and usage of bioresorbable polymers based on polydepsipeptides. The ring-opening polymerization of morpholine-2,5-dione derivatives using organic Sn and enzyme lipase is discussed. The dependence of the macroscopic properties of the block copolymers on their structure is also presented. Bioresorbable polymers based on polydepsipeptides could be used as biomaterials in drug controlled release, tissue engineering scaffolding and shape-memory materials

Development of Terminator–Promoter Bifunctional Elements for Application in <i>Saccharomyces cerevisiae</i> Pathway Engineering

The construction of a genetic circuit requires the substitution and redesign of different promoters and terminators. The assembly efficiency of exogenous pathways will also decrease significantly when the number of regulatory elements and genes is increased. We speculated that a novel bifunctional element with promoter and terminator functions could be created via the fusion of a termination signal with a promoter sequence. In this study, the elements from a Saccharomyces cerevisiae promoter and terminator were employed to design a synthetic bifunctional element. The promoter strength of the synthetic element is apparently regulated through a spacer sequence and an upstream activating sequence (UAS) with a ~5-fold increase, and the terminator strength could be finely regulated by the efficiency element, with a ~5-fold increase. Furthermore, the use of a TATA box-like sequence resulted in the adequate execution of both functions of the TATA box and the efficiency element. By regulating the TATA box-like sequence, UAS, and spacer sequence, the strengths of the promoter-like and terminator-like bifunctional elements were optimally fine-tuned with ~8-fold and ~7-fold increases, respectively. The application of bifunctional elements in the lycopene biosynthetic pathway showed an improved pathway assembly efficiency and higher lycopene yield. The designed bifunctional elements effectively simplified pathway construction and can serve as a useful toolbox for yeast synthetic biology

Research Advances of Microencapsulation and Its Prospects in the Petroleum Industry

Additives in the petroleum industry have helped form an efficient system in the past few decades. Nowadays, the development of oil and gas has been facing more adverse conditions, and smart response microcapsules with the abilities of self-healing, and delayed and targeted release are introduced to eliminate obstacles for further exploration in the petroleum industry. However, limited information is available, only that of field measurement data, and not mechanism theory and structural innovation data. Thus we propose that the basic type, preparation, as well as mechanism of microcapsules partly depend on other mature fields. In this review, we explore the latest advancements in evaluating microcapsules, such as X-ray computed tomography (XCT), simulation, and modeling. Finally, some novel microencapsulated additives with unparalleled advantages, such as flexibility, efficiency, and energy-conservation are described

The novel fluid loss additive HTF-200C for oil field cementing

The domestic fluid loss additives often have lower thermal stability and poor salt-tolerance and their comprehensive properties are not good enough. To solve the problems, a novel cement fluid loss additive HTF-200C, which can resist high temperature and high salt content, was synthesized using the monomers of 2-acrylamido-2-methyl-propane sulphonic acid (AMPS), N, N-dimethyl acrylamide (DMAA) and a new compound with double carboxyl by the method of aqueous solution polymerization. The microstructural characterization and application performance of HTF-200C show that the polymer with the structure of all the monomers has an excellent thermal stability and strong salt tolerance, and can be used in 200 °C or in saturated brine. And the problem of the normal fluid loss additive being easy to hydrolyze due to high temperature can be solved with HTF-200C. What's more, it can also deal with the bulge of thickening curve in consistency test. The cement slurry prepared mainly by HTF-200C presents good comprehensive properties such as low filtration, high thermal stability, strong salt tolerance, rapid development of strength in low temperature, without far delayed solidification, short transit time during thickening process, and so on. The cementing job quality of Well Chengu 1-3 in the Liaohe Oilfield is excellent after it is used. Key words: novel fluid loss additive, HTF-200C, salt-tolerance, temperature-resistance, cement properties, applicatio

A high temperature retarder HTR-300L applied in long cementing interval

With regard to slow development or super retarding happening at the top of cement slurry in deep and ultra-deep wells with long cementing intervals, a new type of retarder HTR-300L was developed and its properties were evaluated. Thickening property tests at different temperatures for slurries with HTR-300L and IR, DSC and TG analysis show that: HTR-300L has good temperature-resistance performance and stable molecular structure. It can be used at the bottom hole circulating temperature of 70 to 200 °C. The thickening time of the slurry can be regulated effectively by adjusting the additive amount of HTR-300L. Thickening property tests for slurries with different salt contents show that HTR-300L has good salt-resistance performance and can be used in salty cement slurry. Strength development, thickening time, fluidity and API filtration of slurries with HTR-300L were studied at different top-bottom temperature differences. The results show that: The slurry with HTR-300L develops well in strength at large temperature difference and can overcome super retarding of the top of the slurry in long cementing interval. HTR-300L is applicable for large temperature range and can be used for slurries with both high and low densities. The slurry with HTR-300L has good overall performance, easy to regulate and control, and can satisfy cementing requirements for long cementing interval. Key words: retarder, cementing, long cementing interval, slurry, thickening tim

Evaluation of discretized transport properties for numerical modelling of heat and moisture transfer in building structures

Over the past decade, a large number of numerical models have been developed to predict heat and moisture transfer within building envelopes. In these models, the moisture transfer mechanism has been described and correlated by reference to the various transport phenomena and corresponding theories, viz. heat transfer and fluid flow. However, predicting the coupled heat and moisture performance of a building construction has never been a straightforward task, since a steady state situation hardly ever occurs and the transport properties (heat and moisture) of a material vary with moisture content and temperature. This paper discusses the transport phenomenon and the various numerical algorithms used in the discretization equations and how different algorithms affect the modelled results. Computer simulations have been conducted for different building materials and material combinations and comparisons have been made to evaluate the selection of discretized transport properties. Discrepancies in results are demonstrated between different mathematical interpolations, namely the Resistance (R ) type formula and Linear ( L ) interpolation. Recommendations are given as guidance towards applying the most appropriate formulations for a given modelling scenario

Dispersion Mechanism of Styrene–Butadiene Rubber Powder Modified by Itaconic Acid and Its Toughening Effect on Oil Well Cement

Styrene–butadiene rubber (SBR) has been extensively applied to enhance the toughness of hardened cement. The instability of existing liquid latex leads to difficulties in storage and transportation, and even performance regression. Thus, the well-dispersed carboxylated butylbenzene (SISBR) latex powders were fabricated through the seed emulsion polymerization of liquid polybutadiene (LPB), styrene (St), itaconic acid (IA), and sodium p-styrenesulfonate (SSS) to overcome the difficulties. The dispersion performance of latex powders with various IA amounts was quantitatively evaluated using particle size distribution, zeta potential, and ultraviolet–visible spectrophotometry. Results showed that the carboxylic ionic (COO-) from IA enhanced the dispersing abilities of SISBR latex powders, which ensured the uniform distribution in water. Based on this, the influence of latex powder on cement was assessed mainly by fluidity, isothermal heat flow calorimetry, X-ray diffraction (XRD), and triaxial mechanical testing. Results showed the fluidity and dispersion performance of cement were improved with more IA in latex, while the hydration of cement was retarded due to excessive adsorption of carboxyl (-COOH) groups in IA. Triaxial mechanical testing showed that cement with SISBR-3 (latex containing 3% IA) exhibited the minimal elastic modulus of 3.16 GPa, which was lower than that of plain cement (8.34 GPa)

High‐Performance Cadmium‐Free Blue Quantum Dot Light‐Emitting Devices with Stepwise Double Hole‐Transport Layers

Abstract ZnSe/ZnS core/shell quantum dots (QDs) are environmental‐friendly blue light‐emitting material, which can easily achieve deep blue emission upon external excitation. However, its deep valence band (VB) and numerous defect states remain handicap to realize sufficient performance of quantum dot light‐emitting diodes (QLEDs). In this work, high‐performance cadmium‐free ZnSe/ZnS QLEDs by constructing a double organic hole‐transport layer (HTL) to obtain carrier balance are presented. The double HTLs, which consist of poly(9,9‐dioctylfluorene‐co‐N‐(4‐butylphenyl)diphenylamine) (TFB) and 2,7‐dioctyl[1]benzothieno[3,2‐b][1]benzothiophene (C8‐BTBT), can suppress the accumulation of electrons between the HTL and the emissive layer (EML), leading to more hole and electron recombination luminescence in QD layer. In addition, the C8‐BTBT layer is conducive to improve the uniformity of QDs film. Thus, the resulting device achieves an external quantum efficiency of 7.23% with TFB/C8‐BTBT double HTLs, which is almost 150% higher than that of traditional devices based on a single hole‐transport layer (4.84%). The authors anticipate that these results can provide a guidance for the optimization of cadmium‐free blue QLEDs