212 research outputs found
Vietnamese EFL Students’ Habits of Using Dictionaries in Translation Practice in ESP Courses
Doing translation tasks, especially in English-for-Specific-Purposes (ESP) courses, is probably demanding and challenging, which requires students’ utilization of dictionaries and other tools. Thus, this study was conducted to investigate Vietnamese English-as-a-Foreign-Language (EFL) students’ habits of dictionary consultation in ESP translation. The data were collected during a three-week period among 75 third-year EFL students from three classes at University of Languages and International Studies (ULIS), Vietnam National University (VNU) by a combination of quantitative and qualitative methods (i.e. survey questionnaires with a combination of close-ended and open-ended questions). The research highlighted the students’ positive attitudes towards dictionary use together with a high level of its frequency in translating ESP texts, their definite preference for dictionary applications for mobile phones and bilingual dictionaries as well as their prioritized lookups such as equivalents, examples, equivalent usage, and word definitions. In addition, it revealed that the students were confident in their capability of exploiting the dictionaries in ESP translation and thus had little desire for teachers’ assistance and guidance
Optical pulse-shaping for internal cooling of molecules
We consider the use of pulse-shaped broadband femtosecond lasers to optically
cool rotational and vibrational degrees of freedom of molecules. Since this
approach relies on cooling rotational and vibrational quanta by exciting an
electronic transition, it is most easily applicable to molecules with similar
ground and excited potential energy surfaces, such that the vibrational state
is usually unchanged during electronic relaxation. Compared with schemes that
cool rotations by exciting vibrations, this approach achieves internal cooling
on the orders-of- magnitude faster electronic decay timescale and is
potentially applicable to apolar molecules. For AlH+, a candidate species, a
rate-equation simulation indicates that rovibrational equilibrium should be
achievable in 8 \mu s. In addition, we report laboratory demonstration of
optical pulse shaping with sufficient resolution and power for rotational
cooling of AlH+
Calculation of Temperature-Dependent Thermal Expansion Coefficient of Metal Crystals Based on Anharmonic Correlated Debye Model
This study aims to calculate the anharmonic thermal expansion (TE) coefficient of metal crystals in the temperature dependence. The calculation model is derived from the anharmonic correlated Debye (ACD) model that is developed using the many-body perturbation approach and correlated Debye model based on the anharmonic effective potential. This potential has taken into account the influence on the absorbing and backscattering atoms of all their nearest neighbors in the crystal lattice. The numerical results for the crystalline zinc (Zn) and crystalline copper (Cu) are in agreement with those obtained by the other theoretical model and experiments at several temperatures. The analytical results show that the ACD model is useful and efficient in analyzing the TE of coefficient of metal crystals
ẢNH HƯỞNG CỦA DỊCH CHIẾT VI KHUẨN LAM ĐẾN NHÂN GIỐNG IN VITRO CÂY LAN HOÀNG THẢO GIẢ HẠC (Dendrobium anosmum Lindl.)
Protocorms of 4-week-old Dendrobium anosmum Lindl. were used as initial material for in vitro propagation. The stock extract of Arthrospira sp. was prepared by grinding 1 g of fresh biomass in 100 mL of distilled water. The in vitro propagation results show that the cyanobacterial extract has the effect of enhancing shoot multiplication and rooting of Dendrobium anosmum. An MS basal medium supplemented with 6 g·L–1 agar, 30 g·L–1 saccharose, and 1.5 mg·L–1 BAP in combination with 20 mL·L–1 cyanobacteria extract was suitable for protocorm multiplication with a protocorm cluster diameters of 2.43 cm. An MS medium supplemented with 6 g·L–1 agar, 30 g·L–1 sucrose, and 1.0 mg·L–1 BAP combined with 20 mL·L–1 cyanobacterial extract was optimal for shoot multiplication. The number of shoots/explant reached 4.7 and a shoot height of 1.37 cm. An MS medium supplemented with 6 g·L–1 agar, 30 g·L–1 sucrose, and 1.5 mg·L–1 NAA in combination with 30 mL·L–1 cyanobacteria extract was the most suitable for rooting with 4.87 roots/bud; the root length was 0.74 cm, and the shoot height was 2.76 cm. These results would open up the application of cyanobacterial extract to reduce costs in plant tissue culture technology.Protocorm của cây lan Hoàng thảo Giả hạc (Dendrobium anosmum Lindl.) bốn tuần tuổi được sử dụng để làm vật liệu khởi đầu cho nhân giống in vitro. Dịch chiết gốc vi khuẩn lam Arthrospira sp. được tạo thành bằng cách nghiền 1 g sinh khối tươi trong 100 mL nước cất. Kết quả cho thấy dịch chiết vi khuẩn lam có tác dụng tăng cường sự nhân chồi và ra rễ của cây lan Hoàng thảo Giả hạc nuôi cấy in vitro. Môi trường MS cơ bản bổ sung 6 g·L–1 agar, 30 g·L–1 saccharose và 1,5 mg·L–1 BAP kết hợp với 20 mL·L–1 dịch chiết vi khuẩn lam thích hợp cho sự nhân protocorm và môi trường tối ưu cho nhân chồi. Đường kính cụm protocorm thu được là 2,43 cm. Môi trường MS cơ bản bổ sung 6 g·L–1 agar, 30 g·L–1 saccharose và 1,0 mg·L–1 BAP kết hợp với 20 mL·L–1 dịch chiết vi khuẩn lam là môi trường tối ưu cho nhân chồi, số chồi/mẫu đạt 4,7; chồi cao 1,37 cm. Môi trường MS cơ bản bổ sung 6 g·L–1 agar, 30 g·L–1 saccharose và 1,5 mg·L–1 NAA kết hợp với 30 mL·L–1 dịch chiết vi khuẩn lam thích hợp nhất cho tạo rễ từ chồi in vitro với 4,87 rễ/chồi; chiều dài rễ là 0,74 cm và chiều cao chồi là 2,76 cm. Kết quả này sẽ mở ra triển vọng ứng dụng dịch chiết vi khuẩn lam giúp giảm chi phí trong công nghệ nuôi cấy mô tế bào thực vật
A cytoplasmic RNA virus generates functional viral small RNAs and regulates viral IRES activity in mammalian cells
The roles of virus-derived small RNAs (vsRNAs) have been studied in plants and insects. However, the generation and function of small RNAs from cytoplasmic RNA viruses in mammalian cells remain unexplored. This study describes four vsRNAs that were detected in enterovirus 71-infected cells using next-generation sequencing and northern blots. Viral infection produced substantial levels (\u3e105 copy numbers per cell) of vsRNA1, one of the four vsRNAs. We also demonstrated that Dicer is involved in vsRNA1 generation in infected cells. vsRNA1 overexpression inhibited viral translation and internal ribosomal entry site (IRES) activity in infected cells. Conversely, blocking vsRNA1 enhanced viral yield and viral protein synthesis. We also present evidence that vsRNA1 targets stem-loop II of the viral 5′ untranslated region and inhibits the activity of the IRES through this sequence-specific targeting. Our study demonstrates the ability of a cytoplasmic RNA virus to generate functional vsRNA in mammalian cells. In addition, we also demonstrate a potential novel mechanism for a positive-stranded RNA virus to regulate viral translation: generating a vsRNA that targets the IRES
Chemistry with Controlled Ions
This chapter focuses on the application of controlled-molecule techniques for precise studies of ion-molecule reactions in the gas phase. It gives an overview of the most important techniques presently used for the control of the translational motion, internal quantum states, and structural properties of molecular ions and neutral molecules in the gas phase. Besides the control of the translational motion, preparation of the internal quantum state of molecular ions is a main prerequisite on the way to controlling chemical reactions. Since the 1980s, (multiphoton) photoionization has been a key method for preparing molecular ions in selected internal states. Various variants of this approach have been implemented. The chapter further gives a brief outline of salient concepts of ion-molecule reaction dynamics which are relevant for the present discussion. Finally, the chapter presents some illustrative examples in which cold- and controlled-molecule techniques have been used to study the mechanisms and dynamics of ionic reactions
The benefits of care: treated HIV infection and health-related quality of life among older-aged people in Uganda.
OBJECTIVES: The objective of this study is to explore how HIV care affects health-related quality of life (HRQoL) among older people in Uganda. METHODS: We enrolled older-aged (≥49 years) people with HIV receiving HIV care and treatment, along with age- and sex-similar people without HIV. We measured health-related quality of life using the EQ-5D-3L scale. RESULTS: People with HIV (n = 298) and people without HIV (n = 302) were similar in median age (58.4 vs. 58.5 years), gender, and number of comorbidities. People with HIV had higher self-reported health status (b = 7.0; 95% confidence interval [CI], 4.2-9.7), higher EQ-5D utility index (b = 0.05; 95% CI, 0.02-0.07), and were more likely to report no problems with self-care (adjusted odds ratio [AOR], 2.0; 95% CI, 1.2-3.3) or pain/discomfort (AOR = 1.8, 95% CI, 1.3-2.8). Relationships between HIV serostatus and health-related quality of life differed by gender, but not age. CONCLUSIONS: Older people with HIV receiving care and treatment reported higher health-related quality of life than people without HIV in Uganda. Access to primary care through HIV programs and/or social network mobilization may explain this difference, but further research is needed to elucidate the mechanisms
High-Density Expression of Ca2+-Permeable ASIC1a Channels in NG2 Glia of Rat Hippocampus
NG2 cells, a fourth type of glial cell in the mammalian CNS, undergo reactive changes in response to a wide variety of brain insults. Recent studies have demonstrated that neuronally expressed acid-sensing ion channels (ASICs) are implicated in various neurological disorders including brain ischemia and seizures. Acidosis is a common feature of acute neurological conditions. It is postulated that a drop in pH may be the link between the pathological process and activation of NG2 cells. Such postulate immediately prompts the following questions: Do NG2 cells express ASICs? If so, what are their functional properties and subunit composition? Here, using a combination of electrophysiology, Ca2+ imaging and immunocytochemistry, we present evidence to demonstrate that NG2 cells of the rat hippocampus express high density of Ca2+-permeable ASIC1a channels compared with several types of hippocampal neurons. First, nucleated patch recordings from NG2 cells revealed high density of proton-activated currents. The magnitude of proton-activated current was pH dependent, with a pH for half-maximal activation of 6.3. Second, the current-voltage relationship showed a reversal close to the equilibrium potential for Na+. Third, psalmotoxin 1, a blocker specific for the ASIC1a channel, largely inhibited proton-activated currents. Fourth, Ca2+ imaging showed that activation of proton-activated channels led to an increase of [Ca2+]i. Finally, immunocytochemistry showed co-localization of ASIC1a and NG2 proteins in the hippocampus. Thus the acid chemosensor, the ASIC1a channel, may serve for inducing membrane depolarization and Ca2+ influx, thereby playing a crucial role in the NG2 cell response to injury following ischemia
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