Dendrobium is known for its pharmacological actions including anti-cancer effect, anti-fatigue effect, gastric ulcer protective effect, and so on. At present, only studies on endophytic fungi of ...Dendrobium affecting the metabolites of host plants have been reported, very little research has been done on endophytic bacteria. In this study, we have demonstrated the great diversity of endophytic bacteria in 6 Dendrobium samples from different origins and cultivars. According to the results of the culture-independent method, the endophytic bacterial community in Dendrobium stems showed obvious different in the 6 samples and was influenced by origin and cultivar. Some bacteria including Ralstonia, Comamonas and Lelliottia were first detected in Dendrobium in this study. Based on the culture-dependent method, a total of 165 cultivable endophytic bacteria isolates were isolated from the sterilized Dendrobium stems, and were classified into 43 species according to the 16S rRNA gene sequence analysis. Moreover, 14 of the 43 strains showed antimicrobial activity against phytopathogen using the Kirby-Bauer method. Strain NA-HTong-7 (Bacillus megaterium, 99.12%) showed the highest antimicrobial activity. This study was the first comprehensive study on endophytic bacteria of Dendrobium from different origins and cultivars, which provides new insights into the endophytic bacteria from Dendrobium.
The link between depression and anxiety status and cancer outcomes has been well-documented but remains unclear. We comprehensively quantified the association between depression and anxiety defined ...by symptom scales or clinical diagnosis and the risk of cancer incidence, cancer-specific mortality, and all-cause mortality in cancer patients. Pooled estimates of the relative risks (RRs) for cancer incidence and mortality were performed in a meta-analysis by random effects or fixed effects models as appropriate. Associations were tested in subgroups stratified by different study and participant characteristics. Fifty-one eligible cohort studies involving 2,611,907 participants with a mean follow-up period of 10.3 years were identified. Overall, depression and anxiety were associated with a significantly increased risk of cancer incidence (adjusted RR: 1.13, 95% CI: 1.06-1.19), cancer-specific mortality (1.21, 1.16-1.26), and all-cause mortality in cancer patients (1.24, 1.13-1.35). The estimated absolute risk increases (ARIs) associated with depression and anxiety were 34.3 events/100,000 person years (15.8-50.2) for cancer incidence and 28.2 events/100,000 person years (21.5-34.9) for cancer-specific mortality. Subgroup analyses demonstrated that clinically diagnosed depression and anxiety were related to higher cancer incidence, poorer cancer survival, and higher cancer-specific mortality. Psychological distress (symptoms of depression and anxiety) was related to higher cancer-specific mortality and poorer cancer survival but not to increased cancer incidence. Site-specific analyses indicated that overall, depression and anxiety were associated with an increased incidence risks for cancers of the lung, oral cavity, prostate and skin, a higher cancer-specific mortality risk for cancers of the lung, bladder, breast, colorectum, hematopoietic system, kidney and prostate, and an increased all-cause mortality risk in lung cancer patients. These analyses suggest that depression and anxiety may have an etiologic role and prognostic impact on cancer, although there is potential reverse causality; Furthermore, there was substantial heterogeneity among the included studies, and the results should be interpreted with caution. Early detection and effective intervention of depression and anxiety in cancer patients and the general population have public health and clinical importance.
Single‐atom catalysts (SACs) with highly active sites atomically dispersed on substrates exhibit unique advantages regarding maximum atomic efficiency, abundant chemical structures, and extraordinary ...catalytic performances for multiple important reactions. In particular, M–N–C SACs (M=transition metal atom) demonstrate optimal electrocatalytic activity for the oxygen reduction reaction (ORR) and have attracted extensive attention recently. Despite substantial efforts in fabricating various M–N–C SACs, the principles for regulating the intrinsic electrocatalytic activity of their active sites have not been sufficiently studied. In this Review, we summarize the regulation strategies for promoting the intrinsic electrocatalytic ORR activity of M–N–C SACs by modulation of the center metal atoms, the coordinated atoms, the environmental atoms, and the guest groups. Theoretical calculations and experimental investigations are both included to afford a comprehensive understanding of the structure–performance relationship. Finally, future directions of developing advanced M–N–C SACs for electrocatalytic ORR and other analogous reactions are proposed.
Regulation strategies for enhancing the intrinsic electrocatalytic oxygen reduction reaction activity of M–N–C single‐atom catalysts are summarized in this review. Four components are considered in the optimization of the catalyst: the center metal atoms, the coordinated atoms, the environmental atoms, and the guest groups.
Red ginseng polysaccharide (RGP) is an active component of the widely used medicinal plant Panax ginseng C. A. Meyer (Araliaceae), which has displayed promising activities against cancer cells. ...However, the detailed molecular mechanism of RGP in ferroptosis is still unknown.
This study evaluates the effects of RGP in cancer cells.
A549 and MDA-MB-231 cells were used. Cell proliferation was measured by CCK-8 assay after being treated with RGP at concentrations of 0, 50, 100, 200, 400, 800 and 1600 μg/mL at 0, 12, 24 and 48 h. Lipid reactive oxygen species (ROS) levels were assessed by C11-BODIPY assay. The control group was treated with PBS.
RGP inhibited human A549 (IC
50
: 376.2 μg/mL) or MDA-MB-231(IC
50
: 311.3 μg/mL) proliferation and induced lactate dehydrogenase (LDH) release, promoted ferroptosis and suppressed the expression of GPX4. Moreover, the effects of RGP were enhanced by the ferroptosis inducer erastin, while abolished by ferroptosis inhibitor ferrostatin-1.
Our study is the first to demonstrate (1) the anticancer activity of RGP in human lung cancer and breast cancer. (2) RGP presented the anti-ferroptosis effects in lung and breast cancer cells via targeting GPX4.
Single‐atom catalysts (SACs) have great potential in electrocatalysis. Their performance can be rationally optimized by tailoring the metal atoms, adjacent coordinative dopants, and metal loading. ...However, doing so is still a great challenge because of the limited synthesis approach and insufficient understanding of the structure–property relationships. Herein, we report a new kind of Mo SAC with a unique O,S coordination and a high metal loading over 10 wt %. The isolation and local environment was identified by high‐angle annular dark‐field scanning transmission electron microscopy and extended X‐ray absorption fine structure. The SACs catalyze the oxygen reduction reaction (ORR) via a 2 e− pathway with a high H2O2 selectivity of over 95 % in 0.10 m KOH. The critical role of the Mo single atoms and the coordination structure was revealed by both electrochemical tests and theoretical calculations.
The cat in the SAC: Mo single‐atom catalysts (SACs) with a unique O,S coordination exhibit outstanding H2O2 selectivity above 95 % in the oxygen reduction reaction (ORR). Electrochemical tests and theoretical calculations revealed the critical role of the coordination structure in SACs, highlighting new opportunities to tune the activity and selectivity in multi‐electron electrocatalysis.
Patients who had any of the following features at the time of, or after, admission were classified as severe cases: (1) respiratory distress (≥30 breaths per min); (2) oxygen saturation at rest ≤93%; ...(3) ratio of partial pressure of arterial oxygen to fractional concentration of oxygen inspired air ≤300 mm Hg; or (4) severe disease complications (eg, respiratory failure, requirement of mechanical ventilation, septic shock, or non-respiratory organ failure). Parameters did not differ significantly between the groups, except that patients in the severe group were significantly older than those in the mild group, as expected.4 No patient died from the infection. 23 (77%) of 30 severe cases received intensive care unit (ICU) treatment, whereas none of the mild cases required ICU treatment. All samples were collected according to WHO guidelines.5 The mean viral load of severe cases was around 60 times higher than that of mild cases, suggesting that higher viral loads might be associated with severe clinical outcomes.
Hypoxia development in tumor is closely associated with its increased aggressiveness and strong resistance to therapy, leading to the poor prognosis in several cancer types. Clinically, invasive ...oxygen microelectrode and high dosage radiotherapy are often utilized to accurately detect and effectively fight hypoxia. Recently, however, there has been a surge of interdisciplinary research aiming at developing functional molecules and nanomaterials that can be used to noninvasively image and efficiently treat hypoxic tumors. In this review, we will provide an overview of the reports published to date on the imaging and therapy of hypoxic tumors. First, we will present the design concepts and engineering of various hypoxia-responsive probes that can be applied to image hypoxia noninvasively, in an order of fluorescent imaging, positron emission tomography, magnetic resonance imaging, and photoacoustic imaging. Then, we will summarize the up-to-date functional nanomaterials which can be used for the effective treatments of tumor hypoxia. The well-established chemical functions of these elaborately designed nanostructures will enable clinicians to adopt specific treatment concepts by overcoming or even utilizing hypoxia. Finally, challenges and future perspectives facing the researchers in the field will be discussed.
Hydrogen peroxide (H2O2) is a green oxidizer widely involved in a vast number of chemical reactions. Electrochemical reduction of oxygen to H2O2 constitutes an environmentally friendly synthetic ...route. However, the oxygen reduction reaction (ORR) is kinetically sluggish and undesired water serves as the main product on most electrocatalysts. Therefore, electrocatalysts with high reactivity and selectivity are highly required for H2O2 electrosynthesis. In this work, a synergistic strategy is proposed for the preparation of H2O2 electrocatalysts with high ORR reactivity and high H2O2 selectivity. A Co−Nx−C site and oxygen functional group comodified carbon‐based electrocatalyst (named as Co–POC–O) is synthesized. The Co–POC–O electrocatalyst exhibits excellent catalytic performance for H2O2 electrosynthesis in O2‐saturated 0.10 m KOH with a high selectivity over 80% as well as very high reactivity with an ORR potential at 1 mA cm−2 of 0.79 V versus the reversible hydrogen electrode (RHE). Further mechanism study identifies that the Co−Nx−C sites and oxygen functional groups contribute to the reactivity and selectivity for H2O2 electrogeneration, respectively. This work affords not only an emerging strategy to design H2O2 electrosynthesis catalysts with remarkable performance, but also the principles of rational combination of multiple active sites for green and sustainable synthesis of chemicals through electrochemical processes.
A synergistic strategy of rational combination of multiple active sites is proposed for high‐performance H2O2 electrosynthesis. Comodification of atomic Co–Nx–C sites and oxygen functional groups on noble‐metal‐free nanocarbon electrocatalysts synergistically renders high reactivity for oxygen reduction and high selectivity for the two‐electron pathway. Consequently, high H2O2 productivity is achieved through a green and sustainable electrochemical approach.
Most of the long‐range intracellular movements of vesicles, organelles and other cargoes are driven by microtubule (MT)‐based molecular motors. Cytoplasmic dynein, a multisubunit protein complex, ...with the aid of dynactin, drives transport of a wide variety of cargoes towards the minus end of MTs. In this article, I review our current understanding of the mechanisms underlying spatiotemporal regulation of dynein‐dynactin‐driven vesicular transport with a special emphasis on the many steps of directional movement along MT tracks. These include the recruitment of dynein to MT plus ends, the activation and processivity of dynein, and cargo recognition and release by the motor complex at the target membrane. Furthermore, I summarize the most recent findings about the fine control mechanisms for intracellular transport via the interaction between the dynein‐dynactin motor complex and its vesicular cargoes.
In a typical mammalian cell, the minus ends of microtubules (MTs) (−) are located within the MT‐organizing center (MTOC) adjacent to the nucleus, and the plus ends (+) point towards the cell periphery. The dynein‐dynactin motor complex moves along the MT track and drives transport of a wide variety of vesicular cargoes towards the minus ends of MTs. This review focuses on the process and regulation of dynein‐dynactin‐driven vesicular transport.
The normalized Laplacian makes a great contribution on analyzing the structure properties of nonregular graphs. Let On be a linear octagonal‐quadrilateral network. In this article, we first concern ...the normalized Laplacian spectrum of On based on the decomposition theorem for the corresponding matrices. Then we derive the closed‐term formulas of the degree‐Kirchhoff index and the number of spanning trees of linear octagonal‐quadrilateral networks on the basis of the relations between the roots and coefficients, respectively.
The degree‐Kirchhoff index and complexity are the important parameters to explore the structural properties of a given network. The normalized Laplacian plays a key role on studying the structure properties of nonregular graphs. The formulas of the degree‐Kirchhoff index and the exactly complexity of the linear octagonal‐quadrilateral graphs are given in terms of the normalized Laplacian.
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