A rapid and specific fluorescent probe based on aggregation-induced emission enhancement for mercury ion detection in living systems.

Mercury is a harmful heavy metal that seriously threatens the environment and organisms. In this study, we combined the aggregation-induced emission mechanism and the advantages of peptides to design a novel tetraphenylene (TPE)-based peptide fluorescent probe, TPE-Cys-Pro-Gly-His (TPE-CPGH), in which the sulfhydryl group of Cys in the peptide chain and the imidazolium nitrogen provided by His were used to mimic the Hg2+ binding site of metalloproteins. The ß-fold formed by Pro-Gly was used to promote the spatial coordination of the probe with Hg2+ and the formation of the coordination complex aggregates, these changes led to the "turn on" response to Hg2+. The detection of Hg2+ by TPE-CPGH not only showed high specificity and sensitivity (LOD=46.2 nM), but also had the advantages of fast response and applicability for detection over a wide pH range. Additionally, TPE-CPGH effectively detected Hg2+ in environmental samples, living cells and organisms due to its low cytotoxicity, high water solubility and cell membrane permeability. More interestingly, TPE-CPGH was also mitigated Hg2+ exposure-induced oxidative stress toxicity in vitro and in vivo.

Self-assembly synthesis of hollow phosphorus-doped graphitic carbon nitride microboxes for the photodegradation of organic pollutants.

The rational design of photocatalysts with efficiency and stability is highly desirable but remains challenging. Here, we report a supramolecular self-assembly strategy to construct hollow phosphorus-doped g-C3N4 microboxes (PCNMs). Considering the effects of multiple parameters on the structure and activity of samples, the orthogonal design is innovatively introduced to optimize technology parameters for screening high-performance g-C3N4. Under visible light irradiation (λ ≥ 420 nm), rhodamine B (RhB, 4 mg L-1) is completely degraded in just 80 seconds in the presence of the optimal PCNM. The kinetic rate constant of RhB degradation with the PCNM is 3.4633 min-1, demonstrating unprecedented activity that is about 112 times higher than that of bulk g-C3N4 (0.0309 min-1) synthesized by direct polycondensation of melamine. Additionally, the optimal PCNM also shows enhanced degradation efficiency for tetracycline. The outstanding properties are primarily attributed to the hollow architecture, high specific surface area, and phosphorus doping. This work advances the design of photocatalysts correlating various factors, opening an avenue for optimizing photocatalytic synthesis and activity.

Proximal femoral tumor resection followed by joint prosthesis replacement: a systematic review and meta-analysis.

BACKGROUND: This study aimed to determine the prognostic outcome of hip joint replacement after resection of proximal femoral tumors by reviewing original studies. METHODS: Two researchers independently searched PubMed, Embase, Cochrane Library, and Web of Science databases from inception to July 17, 2022. Then, the literature was screened by inclusion criteria. The basic information, primary outcomes, and secondary outcomes were extracted for weighted combined analysis. The quality of the included literature was evaluated using the Newcastle-Ottawa scale. RESULTS: Twenty-four retrospective cohort studies comprising 2081 patients were included. The limb salvage rate was 98%. The survival rates at 1, 2, 3, 4, and 5 years were 80, 72, 65, 64, and 55% for patients with primary tumors and the rate at 1, 2, 3, 4, and 5 years were 44, 25, 17, 14, and 11% for patients with bone metastases, respectively. CONCLUSION: As chemotherapy and radiotherapy treatment progressed, joint reconstruction after proximal femoral tumor resection improved patients' function and quality of life.

A Unique Chemo-photodynamic Antitumor Approach to Suppress Hypoxia via Ultrathin Graphitic Carbon Nitride Nanosheets Supported a Platinum(IV) Prodrug.

Tumor hypoxia severely restrains the efficiency of irreversible O2-consumption photodynamic therapy. The deep hypoxia induced by photodynamic therapy can promote the level of hypoxia inducible factor 1α that participates in many tumor processes and eventually lead to poor therapeutic outcomes. Herein, a chemo-photodynamic antitumor strategy based on ultrathin graphitic carbon nitride nanosheets loaded with a hypoxia-targeting platinum(IV) prodrug is reported. Under low-intensity visible light irradiation, such integrated nanosheets effectively generate reactive oxygen species together with DNA binding platinum species to achieve enhanced antiproliferation efficacy by downregulating HIF-1α under hypoxic conditions.

Effect of Ca and Zr Additions on Microstructure and Mechanical Properties of As-Extruded Mg-3Sn Alloy.

In this paper, the effect of Ca and Zr additions on microstructure and mechanical properties at room temperature of Mg-Sn alloys was investigated by comparison of Mg-3Sn (wt.%) (T3), Mg-3Sn-1Ca (wt.%) (TX31), and Mg-3Sn-1Ca-1Zr (wt.%) (TXK311) alloys under extrusion. The results show that the main phases of as-extruded T3 alloy were α-Mg and Mg2Sn phases, while the CaMgSn phase was formed and the precipitation of Mg2Sn phase was inhibited in the TX31 and TXK311 alloys due to the addition of the Ca element. Zr did not form intermetallic compounds with other elements but dissolved in the grains of the matrix and became nucleating particles. Incomplete dynamic recrystallization (DRX) occurred in all alloys during hot extrusion. The coarse rod-like and fine block-like mixed CaMgSn phase was observed in α-Mg matrix of as-extruded samples of the TX31 alloy, and the dispersed granular CaMgSn phase was observed in the TXK311 alloy. Ca inhibited the dynamic recrystallization behavior of the alloys, while Zr promoted the dynamic recrystallization behavior. All the as-extruded alloys exhibit typical fiber texture of {0001} basal//ED. With the addition of Ca and Zr elements, the particle stimulated nucleation (PSN) effect excited by the second phase particles gradually weakened the texture. TXK311 alloy has good comprehensive mechanical properties at room temperature, with tensile strength, yield strength, and elongation of 261 MPa, 244 MPa, and 11%, respectively, and the average grain size was 1.8 µm. Grain refinement and second phase dispersion strengthening are considered to play critical roles in the strength optimization of the TXK311 alloy.

A Strategy for Efficient Preparation of Genus-Specific Diagnostic Antibodies for Snakebites.

As said by former United Nations Secretary-General Kofi Annan, "Snakebite is the most important tropical disease you've never heard of." Listed as a priority neglected tropical disease by the World Health Organization, snakebite envenoming (SBE) kills in excess of 125,000 people per year. However, due to the complexity and overlap of snake venom compositions, few reliable venom diagnostic methods for genus-/species-specific identification, which is crucial for successful SBE therapy, are available. Here, we develop a strategy to select and prepare genus-specific snake venom antibodies, which allows rapid and efficient clinical diagnosis of snakebite. Multi-omics approaches are used to choose candidate antigens from snake venoms and identify genus-specific antigenic epitope peptide fragments (GSAEPs) with ideal immunogenicity, specificity, and spatial accessibility. Double-antibody sandwich ELISA kit was established by matching a polyclonal antibody against a natural antigen and a monoclonal antibody that was prepared by natural protein as antigen and can specifically target the GSAEPs. The kit shows the ability to accurately identify venoms from similar genera of Trimeresurus and Protobothrops with a detection limit of 6.25 ng/ml on the snake venoms and a little cross-reaction, thus proving high feasibility and applicability.

microRNA-3646 serves as a diagnostic marker and mediates the inflammatory response induced by acute coronary syndrome.

Acute coronary syndrome (ACS) is one of the main syndromes of coronary artery disease with high mortality. The identification of biomarkers associated with disease occurrence and progression could improve early detection and risk prediction. This study was aimed to reveal the clinical significance and function of miR-3646 in ACS.The expression of miR-3646 was evaluated in ACS patients, healthy volunteers, and non-ACS patients and estimated the clinical significance of miR-3646. The ACS modeling rats were also established in this study to explore the potential mechanism underlying the function of miR-3646. miR-3646 was upregulated in ACS patients compared with healthy volunteers and non-ACS patients. The expression of miR-3646 was positively correlated with the severity and progression of ACS patients and could discriminate ACS patients from healthy volunteers and non-ACS patients. The knockdown of miR-3646 could reverse the inflammatory response induced by ACS.miR-3646 serves as a diagnostic biomarker for ACS. The knockdown of miR-3646 could alleviate ACS by reversing inflammatory response. These results provide a potential therapeutic target of ACS.

[Mesophyll conductance to CO2: Methods and current knowledge].

Mesophyll conductance (gm), the total conductance of CO2 diffusion from substomatal cavity to the site of carboxylation within chloroplast, is a major limiting factor for photosynthesis and a key parameter for improving photosynthetic resource use efficiency of crops. Online 13C discrimination method is an important method for plant eco-physiological studies and a well-established method for measuring gm of C3 plants, although it has not been widely used due to challenges in methodology and high demands on experimental facilities. In this review, we summarized the characteristics of commonly used methods for gm, introduced the basic theory of the online 13C discrimination method, namely Farquhar's photosynthetic 13C discrimination model; systematically introduced the practical measurements, equations and the components of facilities; and reviewed the drivers for variation in gm of C3 plants. At the last part, we discussed the outlook of the development of methodology, new experimental protocols, and applications in measurement scenarios.

Ghrelin prevents articular cartilage matrix destruction in human chondrocytes.

Osteoarthritis (OA) is the most common form of arthritis worldwide. Excessive production of pro-inflammatory cytokines such as interleukin-1ß (IL-1ß) plays a key role in the pathogenesis of OA. OA is generally characterized by degradation of extracellular matrixes such as type II collagen and aggrecans mediated by matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS). Ghrelin is a secreted peptide hormone regulating appetite and the distribution and rate of use of energy. However, the physiological and pharmacological roles of Ghrelin on the pathological progression of OA haven't been reported before. In the current study, our results indicate that Ghrelin reduced IL-1ß-induced expression of MMP-3, MMP-13, ADAMTS-4 and ADAMTS-5 in a concentration-dependent manner. Notably, Ghrelin ameliorated IL-1ß-induced degradation of type II collagen and aggrecan. Mechanistically, Ghrelin is able to inhibit the expression of IRF-1 mediated by inactivating the JAK2/STAT3 pathway. However, Ghrelin didn't have any impact on IL-1ß induced activation of p38. Taken together, our findings identify a novel function of Ghrelin on inhibiting the degradation of type II collagen and aggrecan.

Troxerutin protects against diabetic cardiomyopathy through NF­κB/AKT/IRS1 in a rat model of type 2 diabetes.

Troxerutin is a bioflavonoid, which can be used to treat venous disorders, thrombosis and cerebrovascular diseases. Recent studies have demonstrated that it may also be used to prevent edemas. However, it is not known whether troxerutin protects against the cardiomyopathic complications of diabetes. In the present study, a rat model of type 2 diabetes was used to investigate the potential for troxerutin to protect against diabetic cardiomyopathy, through changes to nuclear factor­κB (NF­κB) expression. Troxerutin administration significantly reduced heart rate, blood pressure, blood glucose and plasma triglyceride levels across all measured time points. Furthermore, troxerutin significantly reduced reactive oxygen species levels, NF­κB protein expression, and suppressed the phosphorylated forms of AKT, insulin receptor substrate 1 (IRS1) and c­Jun N­terminal kinase (JNK). These results suggested that troxerutin protects against cardiomyopathy via alterations in NF­κB, AKT and IRS1 signaling, in a rat model of type 2 diabetes.

The ultra-rapid synthesis of 2D graphitic carbon nitride nanosheets via direct microwave heating for field emission.

The 2D g-C3N4 nanosheets were ultra-rapidly prepared via a direct microwave heating approach. The as-synthesized g-C3N4 possessed a large surface area, few stacking layers, a large aspect ratio and an enlarged bandgap. As a consequence, the excellent field emission properties of 2D g-C3N4 nanosheets were exhibited with extremely low turn-on fields.

[Anti-angiogenesis of interferon-alpha2b in chronic myeloid leukemia in vitro].

This study was aimed to investigate the anti-angiogenesis of IFN-alpha2b in chronic myeloid leukemia (CML) in vitro by using K562 cell line and human umbilical vein endothelial cells (HUVEC). The levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in culture supernatant of K562 cells were determined by ELISA; the expressions of VEGF and bFGF mRNA after treating K562 cells with 10(3), 10(2) and 10 U/ml IFN-alpha2b for 24, 36, 48 hours were detected by real-time RT-PCR; the effects of K562 cell culture supernatant and IFN-alpha2b on proliferation, migration and differentiation of HUVEC in vitro were assayed by MTT, Transwell chamber and tubule formation assay respectively. The results showed that the K562 cells expressed and secreted VEGF and bFGF. The culture supernatant of K562 cells significantly promoted the proliferation, migration and tubule formation of HUVEC in vitro in a concentration-dependent manner. After treating K562 cells with IFN-alpha2b 10 U/ml for 24, 36 and 48 hours, the expression levels of VEGF and bFGF mRNA were 1.64+/-0.18, 1.49+/-0.14, 1.31+/-0.05 and 1.53+/-0.10, 1.29+/-0.15, 0.79+/-0.13 respectively (p=0.002), but the expression levels of VEGF and bFGF mRNA were not significantly different along with increasing of IFN-alpha2b concentration. It is concluded that the angiogenesis exists in CML. The K562 cell expresses and secrets VEGF and bFGF, which promotes the proliferation, migration and differentiation of HUVEC. The IFN-alpha2b displays anti-angiogenesis by inhibiting the proliferation, migration and tubule formation in vitro of HUVEC and down regulating the expression of VEGF and bFGF mRNA.