Efficient generation of an isolated single-cycle attosecond pulse

A new method for efficiently generating an isolated single-cycle attosecond pulse is proposed. It is shown that the ultraviolet (UV) attosecond pulse can be utilized as a robust tool to control the dynamics of electron wave packets (EWPs). By adding a UV attosecond pulse to an infrared (IR) few-cycle pulse at a proper time, only one return of the EWP to the parent ion is selected to effectively contribute to the harmonics, then an isolated two-cycle 130-as pulse with a bandwidth of 45 eV is obtained. After complementing the chirp, an isolated single-cycle attosecond pulse with a duration less than 100 as seems achievable. In addition, the contribution of the quantum trajectories can be selected by adjusting the delay between the IR and UV fields. Using this method, the harmonic and attosecond pulse yields are efficiently enhanced in contrast to the scheme [G. Sansone {\it et al.}, Science {\bf314}, 443 (2006)] using a few-cycle IR pulse in combination with the polarization gating technique.Comment: 5 pages, 4 figure

Giant enhancement of higher-order harmonics of an optical-tweezer phonon laser

Phonon lasers, as mechanical analogues of optical lasers, are unique tools for not only fundamental studies of phononics but also diverse applications such as acoustic imaging and force sensing. Very recently, by levitating a micro-size sphere in an optical tweezer, higher-order mechanical harmonics were observed in the phonon-lasing regime, as the first step towards nonlinear levitated optomechanics [Nat. Phys. 19, 414 (2023)]. However, both the lasing strengths and the quality factors of the observed harmonics are typically very low, thus severely hindering their applications. Here we show that, by applying a simple but powerful electronic control to such a levitated micro-sphere, three orders of magnitude enhancement are achievable in the brightness of the phonon lasers, including both the fundamental mode and all its higher-order harmonics. Also, giant improvements of their linewidth and frequency stability are realized in such an electro-optomechanical system, together with further improved higher-order phonon coherence. These results, as a significant step forward for enhancing and controlling micro-object phonon lasers, can be readily used for a wide range of applications involving nonlinear phonon lasers, such as acoustic frequency comb, ultra-sound sensing, atmospherical monitoring, and even bio-medical diagnosis of levitated micro-size objects.Comment: 15 pages, 4 figure

Composition and biological activity of tea polysaccharides obtained by water extraction and enzymatic extraction

The composition and biological activities of tea polysaccharides (TPS) obtained by traditional water extraction, boiling water extraction and enzymatic extraction were investigated. Boiling water extraction (100 °C for 2 h) was found to be the optimal method with higher yield of TPS (1.91%) consisting of higher contents of neutral saccharides (57.82%) and acid saccharides (26.95%) with lowest protein content (3.06%). TPS obtained by boiling water extraction exhibited a strong inhibitory effect on α-glucosidase with the inhibitory rate of 86.67%. The inhibitory effect of TPS on α-glucosidase increased with increasing neutral polysaccharides content in TPS. TPS obtained by boiling water extraction (50 μg/mL) had very strong proliferation effect on lymphocyte.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Aptamer-Based Biosensor for Detection of Mycotoxins

Mycotoxins are a large type of secondary metabolites produced by fungi that pose a great hazard to and cause toxic reactions in humans and animals. A majority of countries and regulators, such as the European Union, have established a series of requirements for their use, and they have also set maximum tolerance levels. The development of high sensitivity and a specific analytical platform for mycotoxins is much in demand to address new challenges for food safety worldwide. Due to the superiority of simple, rapid, and low-cost characteristics, aptamer-based biosensors have successfully been developed for the detection of various mycotoxins with high sensitivity and selectivity compared with traditional instrumental methods and immunological approaches. In this article, we discuss and analyze the development of aptasensors for mycotoxins determination in food and agricultural products over the last 11 years and cover the literatures from the first report in 2008 until the present time. In addition, challenges and future trends for the selection of aptamers toward various mycotoxins and aptasensors for multi-mycotoxins analyses are summarized. Given the promising development and potential application of aptasensors, future research studies made will witness the great practicality of using aptamer-based biosensors within the field of food safety.Project of risk assessment on raw milk (GJFP2019026

Characteristics and duties of clinical research nurses: a scoping review

IntroductionThe characteristics and duties of clinical research nurses (CRNs) are constantly developing and changing with the progress of medical technology and increasing needs in patient care. With the continuous deepening and standardization of clinical trials, the importance and status of CRNs during the whole process of clinical trials are also increasingly valued.MethodsA scoping review of studies related to the characteristics and duties of CRNs was conducted to clarify relevant roles and concepts. An electronic search was conducted on three English databases (PubMed, Web of Science, Embase) and two Chinese databases (CNKI and Wanfang database) in December 2023. Two authors independently screened the literature, extracted information from the included literature, and summarized and reported the findings.ResultsA total of 26 articles published between 1991 and 2023 were analyzed, and four characteristics of CRNs were identified as participants and managers of clinical trials, caregivers and protectors of subjects, coordinators of research teams, and educators. Basic knowledge, skills and literacy, communication and coordination ability, and advanced research ability are the competencies required for CRNs.ConclusionFurther studies should focus on the importance of various characteristics of CRNs, so as to improve the quality of clinical trials and promote clinical evidence-based practice

Comparison of Apparent Diffusion Coefficient and T2 Relaxation Time Variation Patterns in Assessment of Age and Disc Level Related Intervertebral Disc Changes

Purpose To compare the variation patterns of ADC and T2 values in different age and intervertebral disc (IVD) levels, thus to identify their sensitivities in assessing age and disc level related IVDs changes. Materials and Methods The T2 and ADC values were recorded from 345 IVDs of 69 volunteers. Kendall's correlation analysis was used to identify the relationship between age and T2/ADC mean values respectively. The one-way analysis of variance (ANOVA) with post hoc analysis was then applied to test the differences of T2 and ADC values among different IVD levels and age groups, followed by linear regression analysis between age (45 years) and T2/ADC mean values. This study was approved by the Ethics Committee of the Chinese Academy of Medical Sciences and the Peking Union Medical College Hospital. Results: Significant negative correlation was observed between age and T2/ADC mean values. The T2 and ADC values showed significant differences among IVD levels and among age groups except for T2 values in age group 1 (25–34 years) and group 2 (35–44 years), and for ADC values at L1–2 level. Both T2 and ADC values showed significant differences between young (age45 years) at each IVD level. A linear relationship was observed between age and T2/ADC mean values in the elderly group as well as in the young group for the ADC mean values, while no such tendency was identified in the young group for the T2 mean values. Conclusions: ADC values may be a more sensitive parameter than T2 in assessing age and disc level related intervertebral disc changes

Identification and functional prediction of long non-coding RNAs related to oxidative stress in the jejunum of piglets

Objective Oxidative stress (OS) is a pathological process arising from the excessive production of free radicals in the body. It has the potential to alter animal gene expression and cause damage to the jejunum. However, there have been few reports of changes in the expression of long noncoding RNAs (lncRNAs) in the jejunum in piglets under OS. The purpose of this research was to examine how lncRNAs in piglet jejunum change under OS. Methods The abdominal cavities of piglets were injected with diquat (DQ) to produce OS. Raw reads were downloaded from the SRA database. RNA-seq was utilized to study the expression of lncRNAs in piglets under OS. Additionally, six randomly selected lncRNAs were verified using quantitative real-time polymerase chain reaction (qRT–PCR) to examine the mechanism of oxidative damage. Results A total of 79 lncRNAs were differentially expressed (DE) in the treatment group compared to the negative control group. The target genes of DE lncRNAs were enriched in gene ontology (GO) terms and Kyoto encyclopedia of genes and genomes (KEGG) signaling pathways. Chemical carcinogenesis-reactive oxygen species, the Foxo signaling pathway, colorectal cancer, and the AMPK signaling pathway were all linked to OS. Conclusion Our results demonstrated that DQ-induced OS causes differential expression of lncRNAs, laying the groundwork for future research into the processes involved in the jejunum’s response to OS

The Factorial Structure of Spatial Abilities in Russian and Chinese Students

Background: Recent research suggested a unifactorial structure of spatial ability (SA). Research is needed to replicate this finding in different populations. Objective: This study aims to explore the factorial structure of SA in samples of 921 Russian and 229 Chinese university students. Design: A gamified spatial abilities battery was administered to all participants. The battery consists of 10 different domains of SA, including 2D and 3D visualization, mental rotation, spatial pattern assembly, spatial relations, spatial planning, mechanical reasoning, spatial orientation and spatial decision making speed and flexibility. Results: The results of the factor analysis showed a somewhat different pattern for different samples. In the Russian sample, the unifactorial structure, shown previously in a large UK sample (Rimfeld et al., 2017), was replicated. A single factor explained 40% of the variance. In the Chinese sample two factors emerged: first factor explained 26% of the variance and the second factor, including only Mechanical reasoning and Cross-Sections tests, explained 14%. The results also showed that the Chinese sample significantly outperformed the Russian sample in 5 out of the 10 tests. Russian students showed better performance only in two of the tests. The effects of all group comparisons were small. Conclusion: Overall, a similar amount of variance in the 10 tests was explained in the two samples, replicating results from the UK sample. Future research is needed to explain the observed differences in the structure of SA

Evaluation of Genetic Susceptibility Loci for Chronic Hepatitis B in Chinese: Two Independent Case-Control Studies

BACKGROUND: A recent genome-wide scan has identified two genetic variants in the HLA-DP region strongly associated with hepatitis B infection in Japanese. This study evaluates the effects of these risk variants in Chinese, where the HBV infection is the most popular in the world. METHODS AND FINDINGS: We have assessed the relationship between these two single nucleotide polymorphisms (rs3077 and rs9277535) and chronic hepatitis B infection in two independent case-control studies. The first population in Chinese Han included 736 patients and 782 spontaneously recovered controls. The second set was established in Chinese Zhuang minority of 177 patients and 208 controls. Both A alleles of rs3077 and rs9277535 significantly deceased the risk to CHB in Chinese Han (OR = 0.540, 95%CI: 0.464-0.628, P = 4.068×10(-16) and OR = 0.696, 95%CI: 0.601-0.806, P = 1.062×10(-6), respectively). Conceivably, rs9277535 was found to be associated with decreased risk of the disease in Chinese Zhuang, with an OR of 0.606 (95%CI, 0.441-0.833, P = 0.002). CONCLUSION: Chronic hepatitis B susceptibility loci in HLA-DP region (rs3077 and rs9277535) identified by genome-wide scan in Japanese population were validated in Chinese population. These findings might provide clues to develop screening and surveillance strategies