Seed plants have evolved to maintain the dormancy of freshly matured seeds until the appropriate time for germination. Seed dormancy and germination are distinct physiological processes, and the ...transition from dormancy to germination is not only a critical developmental step in the life cycle of plants but is also impor- tant for agricultural production. These processes are precisely regulated by diverse endogenous hormones and environmental cues. Although ABA （abscisic acid） and GAs （gibberellins） are known to be the primary phytohormones that antagonistically regulate seed dormancy, recent findings demonstrate that another phytohormone, auxin, is also critical for inducing and maintaining seed dormancy, and therefore might act as a key protector of seed dormancy. In this review, we summarize our current understanding of the sophisticated molecular networks involving the critical roles of phytohormones in regulating seed dormancy and germination, in which AP2-domain-containing transcription factors play key roles. We also discuss the interactions （crosstalk） of diverse hormonal signals in seed dormancy and germination, focusing on the ABA/GA balance that constitutes the central node.
The construct of learned helplessness, as one of the noticeable emotional issues in education, has been investigated and approved its prominent place in education for its stimulus on students' ...accomplishment, enthusiasm, and commitment in learning. Moreover, the role of teachers as the most crucial issues in the learning viewpoint is at the center of attention since they help learners to be more motivated and provide a supportive context by caring. So, the current review of literature tries to emphasize teachers' care and its effects on decreasing learned helplessness in EFL classrooms. The review of this study underscores the important role of the teachers' care and support in learners' improvement of learned helplessness that can be alleviated in this way. Afterward, some suggestions are offered to illuminate the exercise of teachers, learners, teacher trainers, and syllabus designers.
With a cap-and-trade policy and green technology as inputs, we built a manufacturing ordering and pricing joint decision-making model for two downward substitution products to identify the conditions ...for optimal order quantities and prices of products under the additive demand case. Considering the case of a single period model, the conditions required for optimal manufacturing quantities and pricing were discussed, and the construction of the model was analyzed; furthermore, a study of the tactical choices between green technology inputs and manufacturing decisions was conducted, and the conditions required for green technology manufacturing input were obtained.
Synthetic molecular machines have received increasing attention because of their great ability to mimic natural biological motors and create novel modes of motion. However, very few examples have ...been implemented with real autonomous movement inside living cells, due to the challenges of the driving force and highly integrated system design. In this work, we report an elegant, highly integrated DNA nanomachine that can be powered by endogenous ATP molecules and autonomously operated inside living cells without any auxiliary additives. It assembles all components on a single gold nanoparticle (AuNP) including a hairpin-locked swing arm encoding a start triggered by an intracellular target molecule and a two-stranded DNA track responding to the motion of the swing arm. When the intracellular target activates the nanomachine
the unlocking swing arm, the machine autonomously and progressively operates on the established DNA track
intramolecular toehold-mediated strand migration and internal ATP binding. This paper also demonstrates the machine's bioanalytical application for specific microRNA (miRNA) imaging in living cells.
Carbon dots (C-dots) are a kind of fluorescent nanoparticles that are strongly fluorescent, non-blinking, and can be easily synthesized at low cost. Their emission color can be tuned by varying the ...excitation wavelength. Their properties make them strong competitors to semiconductor quantum dots. Synthetic approaches for C-dots can be classified into two categories, viz. top-down and bottom-up methods. Surface passivated and functionalized C-dots can be utilized to sense pH values, metal ions and organic molecules. Owing to their low cytotoxicity, biocompatibility and impressive photostability, long-term observations become possible. C-dots also show promise as labels and for bioimaging. This review (with 142 refs.) is divided into several sections. The first covers commonly used methods for preparation of C-dots including laser ablation, arc discharge, electrochemical methods, pyrolytic processes, template based methods, microwave assisted methods, chemical oxidation methods, reverse micelle based methods, etc. The first section also covers methods for surface functionalization and passivation. We continue by discussing the spectroscopic properties and other physical and chemical properties of C-dots (fluorescence, up-conversion fluorescence, methods for enhancing photoluminescence, effects of pH value, cytotoxicity, etc.). Another section covers the characterization including TEM and XRD. Applications in biology are summarized and subdivided into in vitro imaging, in vivo imaging, chemical probe, quantitation of biomacromolecules, but also in drug delivery, photoacoustic imaging and anticancer therapy. We finally discuss current challenges and perspectives in this promising field.
Graphical Abstract
This review summarizes the commonly used methods for the preparation of C-dots, their surface functionalization, physical and chemical properties, characterization as well as applications and recent advances in the fields of biology and anticancer therapy. We also discuss the challenges and perspectives in this exciting and promising field.
Clear cell renal cell carcinoma (ccRCC) accounts for about 3% of tumors in adults as well as 85% of all primary renal carcinoma. And it is the third most predominant urological carcinoma, but it has ...the maximum mortality rate. Early diagnosis and proper follow‐up of ccRCC patients may improve the prognosis of the illness. Thus, it is imperative to understand the new biomarkers of ccRCC and study new method for the modern therapy of this deadly disease. Furthermore, a large number of microRNAs (miRNAs), small non‐coding RNAs, have been relevant to tumor type, stage, or survival and miRNAs might be progressed as the markers of diagnosis or prognosis in ccRCC. A growing body of data also advised the rationality of regarding miRNAs as therapeutic targets for ccRCC treatment. In this review, we tried to summarize biogenesis of miRNAs and their expression profiles, biological roles, and clinical implications in ccRCC.
In this review, we tried to summarize biogenesis of miRNAs and their expression profiles, biological roles, and clinical implications in clear cell renal cell carcinoma.
Due to the novel optical and optoelectronic properties, 2D materials have received increasing interests for optoelectronics applications. Discovering new properties and functionalities of 2D ...materials is challenging yet promising. Here broadband polarization sensitive photodetectors based on few layer ReS2 are demonstrated. The transistor based on few layer ReS2 shows an n‐type behavior with the mobility of about 40 cm2 V−1 s−1 and on/off ratio of 105. The polarization dependence of photoresponse is ascribed to the unique anisotropic in‐plane crystal structure, consistent with the optical absorption anisotropy. The linear dichroic photodetection with a high photoresponsivity reported here demonstrates a route to exploit the intrinsic anisotropy of 2D materials and the possibility to open up new ways for the applications of 2D materials for light polarization detection.
Polarization sensitive photodetectors are demonstrated based on anisotropic few‐layer ReS2. The transistor based on few layer ReS2 shows an n‐type behavior with a mobility of about 40 cm2 V−1 s−1 and photoresponsivity of about 103 A W−1. The polarization dependence of photoresponse is ascribed to the unique anisotropic structure. The result demonstrates a route to exploit the intrinsic anisotropy of 2D materials and the possibility to open up new ways of the applications of 2D materials for light polarization detection.
During the outbreak of coronavirus disease 2019 (COVID-19), consistent and considerable differences in disease severity and mortality rate of patients treated in Hubei province compared to those in ...other parts of China have been observed. We sought to compare the clinical characteristics and outcomes of patients being treated inside and outside Hubei province, and explore the factors underlying these differences.
Collaborating with the National Health Commission, we established a retrospective cohort to study hospitalised COVID-19 cases in China. Clinical characteristics, the rate of severe events and deaths, and the time to critical illness (invasive ventilation or intensive care unit admission or death) were compared between patients within and outside Hubei. The impact of Wuhan-related exposure (a presumed key factor that drove the severe situation in Hubei, as Wuhan is the epicentre as well the administrative centre of Hubei province) and the duration between symptom onset and admission on prognosis were also determined.
At the data cut-off (31 January 2020), 1590 cases from 575 hospitals in 31 provincial administrative regions were collected (core cohort). The overall rate of severe cases and mortality was 16.0% and 3.2%, respectively. Patients in Hubei (predominantly with Wuhan-related exposure, 597 (92.3%) out of 647) were older (mean age 49.7
44.9 years), had more cases with comorbidity (32.9%
19.7%), higher symptomatic burden, abnormal radiologic manifestations and, especially, a longer waiting time between symptom onset and admission (5.7
4.5 days) compared with patients outside Hubei. Patients in Hubei (severe event rate 23.0%
11.1%, death rate 7.3%
0.3%, HR (95% CI) for critical illness 1.59 (1.05-2.41)) have a poorer prognosis compared with patients outside Hubei after adjusting for age and comorbidity. However, among patients outside Hubei, the duration from symptom onset to hospitalisation (mean 4.4
4.7 days) and prognosis (HR (95%) 0.84 (0.40-1.80)) were similar between patients with or without Wuhan-related exposure. In the overall population, the waiting time, but neither treated in Hubei nor Wuhan-related exposure, remained an independent prognostic factor (HR (95%) 1.05 (1.01-1.08)).
There were more severe cases and poorer outcomes for COVID-19 patients treated in Hubei, which might be attributed to the prolonged duration of symptom onset to hospitalisation in the epicentre. Future studies to determine the reason for delaying hospitalisation are warranted.
Photodynamic therapy (PDT) is considered a promising approach for the treatment of cancer and is achieved via the photosensitizer (PS)-mediated incomplete reduction of oxygen upon light irradiation, ...which generates high levels of reactive oxygen species (ROS) to induce potent vascular damage and to directly kill tumor cells. However, there is an undesirable impediment with this approach in that tumor tissues generally suffer from serious hypoxia, which significantly affects the efficiency of PDT. Additionally, PDT that consumes oxygen will further aggravate tumor hypoxia, thus potentially leading to multiple undesirable consequences, such as angiogenesis, tumor invasiveness, and tumor metastasis. This mini-review provides a comprehensive overview of the recent research progress on overcoming or utilizing tumor hypoxia to enhance the therapeutic efficacy of PDT.
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