Genetic adaptation of skin pigmentation in highland Tibetans.

Strong ultraviolet (UV) radiation at high altitude imposes a serious selective pressure, which may induce skin pigmentation adaptation of indigenous populations. We conducted skin pigmentation phenotyping and genome-wide analysis of Tibetans in order to understand the underlying mechanism of adaptation to UV radiation. We observe that Tibetans have darker baseline skin color compared with lowland Han Chinese, as well as an improved tanning ability, suggesting a two-level adaptation to boost their melanin production. A genome-wide search for the responsible genes identifies GNPAT showing strong signals of positive selection in Tibetans. An enhancer mutation (rs75356281) located in GNPAT intron 2 is enriched in Tibetans (58%) but rare in other world populations (0 to 18%). The adaptive allele of rs75356281 is associated with darker skin in Tibetans and, under UVB treatment, it displays higher enhancer activities compared with the wild-type allele in in vitro luciferase assays. Transcriptome analyses of gene-edited cells clearly show that with UVB treatment, the adaptive variant of GNPAT promotes melanin synthesis, likely through the interactions of CAT and ACAA1 in peroxisomes with other pigmentation genes, and they act synergistically, leading to an improved tanning ability in Tibetans for UV protection.

Micropeptides: potential treatment strategies for cancer.

Some noncoding RNAs (ncRNAs) carry open reading frames (ORFs) that can be translated into micropeptides, although noncoding RNAs (ncRNAs) have been previously assumed to constitute a class of RNA transcripts without coding capacity. Furthermore, recent studies have revealed that ncRNA-derived micropeptides exhibit regulatory functions in the development of many tumours. Although some of these micropeptides inhibit tumour growth, others promote it. Understanding the role of ncRNA-encoded micropeptides in cancer poses new challenges for cancer research, but also offers promising prospects for cancer therapy. In this review, we summarize the types of ncRNAs that can encode micropeptides, highlighting recent technical developments that have made it easier to research micropeptides, such as ribosome analysis, mass spectrometry, bioinformatics methods, and CRISPR/Cas9. Furthermore, based on the distribution of micropeptides in different subcellular locations, we explain the biological functions of micropeptides in different human cancers and discuss their underestimated potential as diagnostic biomarkers and anticancer therapeutic targets in clinical applications, information that may contribute to the discovery and development of new micropeptide-based tools for early diagnosis and anticancer drug development.

A double-edged sword: role of apoptosis repressor with caspase recruitment domain (ARC) in tumorigenesis and ischaemia/reperfusion (I/R) injury.

Apoptosis repressor with caspase recruitment domain (ARC) acts as a potent and multifunctional inhibitor of apoptosis, which is mainly expressed in postmitotic cells, including cardiomyocytes. ARC is special for its N-terminal caspase recruitment domain and caspase recruitment domain. Due to the powerful inhibition of apoptosis, ARC is mainly reported to act as a cardioprotective factor during ischaemia‒reperfusion (I/R) injury, preventing cardiomyocytes from being devastated by various catastrophes, including oxidative stress, calcium overload, and mitochondrial dysfunction in the circulatory system. However, recent studies have found that ARC also plays a potential regulatory role in tumorigenesis especially in colorectal cancer and renal cell carcinomas, through multiple apoptosis-associated pathways, which remains to be explored in further studies. Therefore, ARC regulates the body and maintains the balance of physiological activities with its interesting duplex. This review summarizes the current research progress of ARC in the field of tumorigenesis and ischaemia/reperfusion injury, to provide overall research status and new possibilities for researchers.

Controllable Solid-Phase Fabrication of an Fe2O3/Fe5C2/Fe-N-C Electrocatalyst toward Optimizing the Oxygen Reduction Reaction in Zinc-Air Batteries.

Preparing advanced electrocatalysts via solid-phase reactions encounters the challenge of low controllability for multiconstituent hybridization and microstructure modulation. Herein, a hydrothermal-mimicking solid-phase system is established to fabricate novel Fe2O3/Fe5C2/Fe-N-C composites consisting of Fe2O3/Fe5C2 nanoparticles and Fe,N-doped carbon species with varying morphologies. The evolution mechanism featuring a competitive growth of different carbon sources in a closed hypoxic space is elucidated for a series of Fe2O3/Fe5C2/Fe-N-C composites. The size and dispersity of Fe2O3/Fe5C2 nanoparticles, the graphitization degree of the carbonaceous matrix, and their diverse hybridization states lead to disparate electrocatalytic behaviors for the oxygen reduction reaction (ORR). Among them, microspherical Fe2O3/Fe5C2/Fe-N-C-3 exhibits an optimal ORR performance and the as-assembled zinc-air battery shows all-round superiority to the Pt/C counterpart. This work presents a mild solid-phase fabrication technique for obtaining a variety of nanocomposites with effective control over composition hybridization and microstructural modulation, which is significantly important for the design and optimization of advanced electrocatalysts.

Amino Phenyl Copper Phosphate-Bridged Reactive Phosphaphenanthrene to Intensify Fire Safety of Epoxy Resins.

To improve the compatibility between flame retardant and epoxy resin (EP) matrix, amino phenyl copper phosphate-9, 10-dihydro-9-oxygen-10-phospha-phenanthrene-10-oxide (CuPPA-DOPO) is synthesized through surface grafting, which is blended with EP matrix to prepare EP/CuPPA-DOPO composites. The amorphous structure of CuPPA-DOPO is characterized by X-ray diffraction and Fourier-transform infrared spectroscopy. Scanning electron microscope (SEM) images indicate that the agglomeration of hybrids is improved, resisting the intense intermolecular attractions on account of the acting force between CuPPA and DOPO. The results of thermal analysis show that CuPPA-DOPO can promote the premature decomposition of EP and increase the residual amount of EP composites. It is worth mentioning that EP/6 wt% CuPPA-DOPO composites reach UL-94 V-1 level and limiting oxygen index (LOI) of 32.6%. Meanwhile, their peak heat release rate (PHRR), peak smoke production release (PSPR) and CO2 production (CO2P) are decreased by 52.5%, 26.1% and 41.4%, respectively, compared with those of EP. The inhibition effect of CuPPA-DOPO on the combustion of EP may be due to the release of phosphorus and ammonia free radicals, as well as the catalytic charring ability of metal oxides and phosphorus phases.

Effect of Layered Aminovanadic Oxalate Phosphate on Flame Retardancy of Epoxy Resin.

To alleviate the fire hazard of epoxy resin (EP), layered ammonium vanadium oxalate-phosphate (AVOPh) with the structural formula of (NH4)2[VO(HPO4)]2(C2O4)·5H2O is synthesized using the hydrothermal method and mixed into an EP matrix to prepare EP/AVOPh composites. The thermogravimetric analysis (TGA) results show that AVOPh exhibits a similar thermal decomposition temperature to EP, which is suitable for flame retardancy for EP. The incorporation of AVOPh nanosheets greatly improves the thermal stability and residual yield of EP/AVOPh composites at high temperatures. The residue of pure EP is 15.3% at 700 °C. In comparison, the residue of EP/AVOPh composites is increased to 23.0% with 8 wt% AVOPh loading. Simultaneously, EP/6 wt% AVOPh composites reach UL-94 V1 rating (t1 + t2 =16 s) and LOI value of 32.8%. The improved flame retardancy of EP/ AVOPh composites is also proven by the cone calorimeter test (CCT). The results of CCT of EP/8 wt% AVOPh composites show that the peak heat release rate (PHHR), total smoke production (TSP), peak of CO production (PCOP), and peak of CO2 production (PCO2P) decrease by 32.7%, 20.4%, 37.1%, and 33.3% compared with those of EP, respectively. This can be attributed to the lamellar barrier, gas phase quenching effect of phosphorus-containing volatiles, the catalytic charring effect of transition metal vanadium, and the synergistic decomposition of oxalic acid structure and charring effect of phosphorus phase, which can insulate heat and inhibit smoke release. Based on the experimental data, AVOPh is expected to serve as a new high-efficiency flame retardant for EP.

The Synthesis and Polymer-Reinforced Mechanical Properties of SiO2 Aerogels: A Review.

Silica aerogels are considered as the distinguished materials of the future due to their extremely low thermal conductivity, low density, and high surface area. They are widely used in construction engineering, aeronautical domains, environmental protection, heat storage, etc. However, their fragile mechanical properties are the bottleneck restricting the engineering application of silica aerogels. This review briefly introduces the synthesis of silica aerogels, including the processes of sol-gel chemistry, aging, and drying. The effects of different silicon sources on the mechanical properties of silica aerogels are summarized. Moreover, the reaction mechanism of the three stages is also described. Then, five types of polymers that are commonly used to enhance the mechanical properties of silica aerogels are listed, and the current research progress is introduced. Finally, the outlook and prospects of the silica aerogels are proposed, and this paper further summarizes the methods of different polymers to enhance silica aerogels.

Moving MoO2/C Nanospheres with the Functions of Enrichment and Sensing for Online-High-Throughput SERS Detection.

The development of online surface-enhanced Raman spectroscopy (SERS) detection methods is crucial to achieving high-throughput efficiency. Herein, a non-noble-metal moving substrate that integrates the functions of enrichment and sensing is developed for the microfluidic online-high-throughput detection of pollutants. The lowest limit of detection of 1 × 10-12 M and a Raman enhancement factor of 6.3 × 108 are obtained on the nanospheres. In a single detection channel, the analysis of 20 samples is achieved within 5 min, and the relative standard deviation of the signals is less than 6.8%. Compared with static SERS detection of fixed substrates, this dynamic SERS detection method greatly reduces the contamination memory effect of the analyte residue, enabling it to perform the sequential quantitative detection of samples with large concentration differences. Moreover, the current online SERS platform realizes the rapid quantitative detection of multicomponent samples.

Selective Preparation of Mo2N and MoN with High Surface Area for Flexible SERS Sensing.

γ-Mo2N and δ-MoN are the two most important molybdenum nitrides, but controllable preparation of them with high surface area has not been achieved. Herein, we achieved selective preparation of γ-Mo2N and δ-MoN. The key factor for the selective preparation of γ-Mo2N and δ-MoN is to control the crystal phase of the precursor MoO3. In H2O and NH3 mixed gas, the α-MoO3 nanoribbons are nitridated to obtain γ-Mo2N single-crystal porous nanobelts, while the h-MoO3 prisms are nitrided to obtain δ-MoN hierarchical porous columns. The corrosion effect of H2O plays a key role in the formation of single-crystal porous structure. The γ-Mo2N flexible membrane composed of the single-crystal porous nanobelts exhibits strong localized surface plasmon resonance and surface enhanced Raman scattering effect, which show highly sensitive response to polychlorinated phenol.

General Microwave Route to Single-Crystal Porous Transition Metal Nitrides for Highly Sensitive and Stable Raman Scattering Substrates.

The synthesis of metallic transition metal nitrides (TMNs) has traditionally been performed under harsh conditions, which makes it difficult to prepare TMNs with high surface area and porosity due to the grain sintering. Herein, we report a general and rapid (30 s) microwave synthesis method for preparing TMNs with high specific surface area (122.6-141.7 m2 g-1) and porosity (0.29-0.34 cm3 g-1). Novel single-crystal porous WN, Mo2N, and V2N are first prepared by this method, which exhibits strong surface plasmon resonance, photothermal conversion, and surface-enhanced Raman scattering effects. Different from the conventional low-temperature microwave absorbing media such as water and polymers, as new concept absorbing media, hydrated metal oxides and metallic metal oxides are found to have a remarkable high-temperature microwave heating effect and play key roles in the formation of TMNs. The current research results provide a new-concept microwave method for preparing high lattice energy compounds with high specific surface.

The combination of Biochanin A and SB590885 potentiates the inhibition of tumour progression in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most aggressive and frequently diagnosed malignancy of the liver. Despite aggressive therapy, life expectancy of many patients in these cases is extended by only a few months. Hepatocellular carcinoma (HCC) has a particularly poor prognosis and would greatly benefit from more effective therapies. METHODS: The CCK-8 assay and colony formation assays were used to test the cell proliferation and viability. The effects of combination Biochanin A and SB590885 on apoptosis and cell cycle arrest of HCC cells were analysed by flow cytometry. The expression of ERK MAPK and PI3K/AKT/mTOR signalling as well as apoptosis and cell cycle-related proteins in HCC cells were tested by western blotting. The HCC cell xenograft model was established to test the tumor proliferation. Serum and plasma were tested for liver and kidney safety markers (ALP, ALT, AST, total bilirubin, creatinine, urea nitrogen) by using SpectraMax i3X. RESULTS: The combination of natural product Biochanin A with the BRAF inhibitor SB590885 synergistically suppressed proliferation, and promoted cell cycle arrest and apoptosis in vitro. Furthermore, we demonstrated that the combination of Biochanin A and SB590885 led to increased impairment of proliferation and HCC tumour inhibition through disrupting of the ERK MAPK and the PI3K/AKT pathways in vitro. The volumes tumors and the weights of tumours were significantly reduced by the combination treatment compared to the control or single treatments in vivo. In addition, we found that there was no significant hepatorenal toxicity with the drug combination, as indicated by the hepatorenal toxicity test. CONCLUSION: The results identify an effective combination therapy for the most aggressive form of HCC and provide the possibility of therapeutic improvement for patients with advanced HCC.

Darwinian Positive Selection on the Pleiotropic Effects of KITLG Explain Skin Pigmentation and Winter Temperature Adaptation in Eurasians.

Human skin color diversity is considered an adaptation to environmental conditions such as UV radiation. Investigations into the genetic bases of such adaptation have identified a group of pigmentation genes contributing to skin color diversity in African and non-African populations. Here, we present a population analysis of the pigmentation gene KITLG with previously reported signal of Darwinian positive selection in both European and East Asian populations. We demonstrated that there had been recurrent selective events in the upstream and the downstream regions of KITLG in Eurasian populations. More importantly, besides the expected selection on the KITLG variants favoring light skin in coping with the weak UV radiation at high latitude, we observed a KITLG variant showing adaptation to winter temperature. In particular, compared with UV radiation, winter temperature showed a much stronger correlation with the prevalence of the presumably adaptive KITLG allele in Asian populations. This observation was further supported by the in vitro functional test at low temperature. Consequently, the pleiotropic effects of KITLG, that is, pigmentation and thermogenesis were both targeted by natural selection that acted on different KITLG sequence variants, contributing to the adaptation of Eurasians to both UV radiation and winter temperature at high latitude areas.

Improving Fire Safety of Epoxy Resin with Alkyl Glycoside Modified CuAl-Layered Double Hydroxide.

To further improve carbonization efficiency of epoxy resin (EP) composites to form compact protective layers during combustion process, alkyl glycoside modified CuAl layered double hydroxide (CuAl-(APG)LDH) was designed and synthesized via one-step coprecipitation method, which was incorporated into EP matrix for preparing EP/CuAl-(APG)LDH nanocomposites. The results of XRD and TEM confirmed that EP nanocomposites with low incorporation of CuAl-(APG)LDH were exfoliated structures. The TGA results showed that the incorporation of CuAl-(APG)LDH remarkably increased the residues at 700 °C. The improved flame retardancy of EP/CuAl-(APG)LDH nanocomposites was proved by cone calorimeter test. The peak heat release rate, total heat release, peak smoke production rate and total smoke production value of EP/4 wt%CuAl-(APG)LDH nanocomposites dramatically decreased, which were attributed to the formation of hard and condensed residual layers on the surface of EP/CuAl-(APG)LDH nanocomposites.

Functionalized Montmorillonite Intercalation Iron Compounds for Improving Flame Retardancy of Epoxy Resin Nanocomposites.

To endow montmorillonite with excellent flame retardancy, montmorillonite (Mt) intercalation iron compounds (Fe-Mt) were synthesized and modified by phosphorylated chitosan (PCTS) to prepare PCTS modified Fe-Mt (PCTS-Fe-OMt). PCTS-Fe-OMt was further incorporated into epoxy resin (EP) for improving the fire safety of EP. The results revealed that the interlayer spacing of Fe-Mt was expanded by PCTS, which resulted in well dispersion of PCTS-Fe-OMt in EP matrix. The TGA results showed that EP/PCTS-Fe-OMt nanocomposites exhibited much higher residues due to the excellent charring performance of PCTS-Fe-OMt. According to the cone calorimeter tests, the addition of 5 wt% PCTS-Fe-OMt made peak heat release rate, total heat release, peak smoke production rate, total smoke production values of EP observably decrease by 40.2%, 17.1%, 33.9% and 19.0%. Based on the above results, the improved flame retardancy and smoke suppression properties of EP/PCTS-Fe-OMt nanocomposites were attributed to the combination of iron compounds and phosphorylated chitosan on catalytic charring, thereby promoting the formation of swollen, continuous and compact char layers on the surface of polymer during combustion, eventually restraining the decomposition of polymers.

Improving the Thermal Stability and Flame Retardancy of PP/IFR Composites by NiAl-Layered Double Hydroxide.

Nickel and aluminum layered double hydroxide (NiAl-LDH) was synthesized via co-precipitation and modified by sodium dodecyl sulfate (SDS), which was marked as NiAl-OLDH. The structure of NiAl-LDH was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In order to investigate the role of LDH on polymer/intumescent flame retardant (IFR) systems, polypropylene (PP)/IFR/NiAl-OLDH nanocomposites were prepared by melt intercalation. Thermal and flame retardant properties of PP/IFR/NiAl-OLDH nanocomposites were studied. The results indicated that incorporation of NiAl-OLDH in PP/IFR composites significantly improved the thermal stability, flame retardancy and smoke suppression properties. With the addition of 5 wt% NiAl-OLDH, PP/IFR/NiAl-OLDH nanocomposites obtained UL-94 V0 level and the LOI value reached 27.5%. Compared with those of PP/IFR, the peak heat release rate (PHRR), total heat release (THR) and peak smoke production rate (PSPR) values reduced 49%, 10%, and 63%, respectively, which were attributed to the barrier effect and excellent charring performance of NiAl-OLDH.

Thermal Stability and Flame Retardancy of Polypropylene/NiAl Layered Double Hydroxide Nanocomposites.

NiAl layered double hydroxide (NiAl-LDH) was synthesized by co-precipitation method. And sodium dodecyl sulphate (SDS) as modifier was utilized to enlarge the d-spacing of NiAl-LDH to obtain SDS-NiAl-LDH. PP/SDS-NiAl-LDH nanocomposites were prepared with different amount of SDS- NiAl-LDH and PP by melt intercalation method. The results of XRD and TEM confirmed that intercalated and exfoliated-intercalated structures were formed. Compared with pure PP, PP/SDS- NiAl-LDH nanocomposites exhibited high thermal stability and residual to the presence of barrier effect of NiAl-LDH layers. Cone calorimetry analysis indicated that incorporation of SDS-NiAl-LDH obviously improved flame retardancy and smoke suppression properties of PP. With the addition of 5 wt% SDS-NiAl-LDH, the peak heat release rate (PHRR), the total heat release (THR) and smoke production rate (SPR) peak values reduced 32.4%, 16.0%, and 61.5% compared with those of pure PP, which were attributed to the barrier effect and excellent charing performance of SDS-NiAl-LDH.

Fabrication of Porous ZnO/Co3O4 Composites for Improving Cycling Stability of Supercapacitors.

To tackle the issue of poor cycling stability for metal oxide nanoparticles as supercapacitor electrode, porous ZnO/Co3O4 composites were fabricated via solid-state thermolysis of [CoZn(BTC)(NO3)](2H2O)(0.5DMF) under air atmosphere. The results demonstrate that the products are mesoporous polyhedron structure with the diameter of about 10 µm, which are constructed by many interconnected nanocrystals with the sizes of around 20 nm. ZnO/Co3O4 composites as supercapacitor electrode exhibited excellent cyclic stability capacity, showing a maximum specific capacitance of 106.7 F g-1 and a capacity retention of 102.7 F · g-1 after 1000 cycles at 0.5 A · g-1. The superior electrochemical performance was contributed to ZnO/Co3O4 composites with porous structures and small size, which shortened the route of electronic transmission as well as ions insertion and desertion processes. Additionally, the synergetic effect of bimetallic oxides improved the electrochemical stability.

Graphene Oxide Nanocoating Prevents Flame Spread on Polyurethane Sponge.

Many current flame retardant technologies for polymeric materials contain environmentally harmful compounds, negatively impact processing and mechanical properties. In an effort to tackle these issues, graphene oxide (GO) nanocoating was deposited on the surface of polyurethane sponge (PUS) to reduce its flammability via layer-by-layer (LbL) assembly method. The results indicated that GO was evenly distributed on the surface of PUS to form GO coating PUS (PUS@GO) composites. This coating system completely eliminated melt dripping of sponge upon exposure to the direct flame from a butane torch. According to the result of cone calorimeter test, PUS@GO composites exhibited excellent flame retardancy. In particular, PUS@GO composites submerging into 5 mg · mL-1 GO suspension, had significant reduction in the PHRR value (53.3%), THR value (35.9%), SPR value (61.8%), TSR value (81.9%), and peak CO production value (65.8%). Such significant improvement in flame retardancy suggested that GO nanosheets were good candidate as a flame-retardant LbL coating to reduce the flammability of PUS.

A Novel Naphthyridine Derivative, 3u, Induces Necroptosis at Low Concentrations and Apoptosis at High Concentrations in Human Melanoma A375 Cells.

Naphthyridine derivatives are a widely-used class of heterocycles due to their pharmacological activities. A novel compound (10-Methoxy-1,2,3,4-tetrahydrobenzo(g)(1,3) diazepino(1,2-a)-(1,8)naphthyridin-6-yl)(phenyl) methanone (named 3u), showed good anticancer activity in the human malignant melanoma cell line A375 via Thiazolyl Blue Tetrazolium Bromide (MTT) assay. After Western blotting confirmed, we found that 3u induces necroptosis at low concentrations and apoptosis at high concentrations via the upregulation of death receptors and scaffold protein in A375 cells. Furthermore, by combining 3u with the caspase inhibitor zVAD-fmk or Receptor Interacting Serine/Threonine Kinase 1 (RIP1) kinase inhibitor Necrostatin-1 (Nec-1), we found that the activity of caspase-8 was the crucial factor that determined whether either apoptosis or necroptosis occurred. The results indicate that 3u should be considered as a potential chemical substance for melanoma treatment.

The opioid receptor triple agonist DPI-125 produces analgesia with less respiratory depression and reduced abuse liability.

Opioid analgesics remain the first choice for the treatment of moderate to severe pain, but they are also notorious for their respiratory depression and addictive effects. This study focused on the pharmacology of a novel opioid receptor mixed agonist DPI-125 and attempted to elucidate the relationship between the δ-, µ- and κ-receptor potency ratio and respiratory depression and abuse liability. Five diarylmethylpiperazine compounds (DPI-125, DPI-3290, DPI-130, KUST202 and KUST13T02) were selected for this study. PKA fluorescence redistribution assays in CHO cells individually expressing δ-, µ- or κ-receptors were used to measure the agonist potency. The respiratory safety profiles were estimated in rats by the ratio of ED50 (pCO2 increase)/ED50 (antinociception). The abuse liability of DPI-125 was evaluated with a self-administration model in rhesus monkeys. The observed agonist potencies of DPI-125 for δ-, µ- and κ-opioid receptors were 4.29±0.36, 11.10±3.04, and 16.57±4.14 nmol/L, respectively. The other four compounds were also mixed agonists with varying potencies. DPI-125 exhibited a high respiratory safety profile, clearly related to its high δ-receptor potency. The ratio of the EC50 potencies for the µ- and δ-receptors was found to be positively correlated with the respiratory safety ratio. DPI-125 has similar potencies for µ- and κ-receptors, which is likely the reason for its reduced abuse potential. Our results demonstrate that the opioid receptor mixed agonist DPI-125 is safer and less addictive than traditional µ-agonist analgesics. These findings suggest that the development of δ>µâˆ¼κ opioid receptor mixed agonists is feasible, and such compounds could represent a promising class of potent analgesics with wider therapeutic windows.