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1.
Chem Commun (Camb) ; 60(39): 5136-5148, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38656314

RESUMO

Hydrogen production via the photocatalytic water splitting reaction on semiconductors presents a promising avenue to directly achieve solar energy conversion and storage. Bismuth-based semiconductors with layered structures, a hierarchical arrangement of components stacked in the form of two-dimensional extended layers where the atoms within each layer are typically strongly bonded, while the interactions between the layers are relatively weak, have emerged as an important series of photocatalyst candidates. In this review, we focus on the new emerging layered bismuth-based semiconductors with structures in Sillén, Aurivillius, Sillén-Aurivillius and bismuth chromate systems primarily employed in the photocatalytic water splitting reaction. From a crystal structure-oriented view, we delve into discussions on how the component and unit of a crystal structure influence the intrinsic properties, including light absorption and photogenerated charge transfer and separation, of materials as well as the corresponding photocatalytic performance of the water splitting reaction. The strategies for modulating the ferroelectricity and surface modification of these layered bismuth-based semiconductors are also involved. We also discuss the limitations of these materials accompanied by a forward-looking perspective, and we hope to provide some insights from the view of rational material design and engineering for the fabrication of high-efficiency photocatalytic water splitting systems.

2.
Talanta ; 273: 125924, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38518717

RESUMO

Wildlife conservation is often challenged by a lack of knowledge about the reproduction biology and adaptability of endangered species. Although monitoring steroids and related molecules can increase this knowledge, the applicability of current techniques (e.g. immunoassays) is hampered by species-specific steroid metabolism and the requisite to avoid invasive sampling. This study presents a validated steroidomics method for the (un)targeted screening of a wide range of sex and stress steroids and related molecules in urine using ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS). In total, 50 steroids (conjugated and non-conjugated androgens, estrogens, progestogens and glucocorticoids) and 6 prostaglandins could be uniquely detected. A total of 45 out of 56 compounds demonstrated a detection limit below 0.01 ng µL-1. Excellent linearity (R2 > 0.99), precision (CV < 20 %), and recovery (80-120 %) were observed for 46, 41, and 39 compounds, respectively. Untargeted screening of pooled giant panda and human samples yielded 9691 and 8366 features with CV < 30 %, from which 84.1 % and 83.0 %, respectively, also demonstrated excellent linearity (R2 > 0.90). The biological validity of the method was investigated on male and female giant panda urine (n = 20), as well as pooled human samples (n = 10). A total of 24 different steroids were detected with clear qualitative and quantitative differences between human and giant panda samples. Furthermore, expected differences were revealed between female giant panda samples from different reproductive phases. In contrast to traditional biomonitoring techniques, the developed steroidomics method was able to screen a wide range of compounds and provide information on the putative identities of metabolites potentially important for reproductive monitoring in giant pandas. These results illustrate the advancements steroidomics brings to the field of wildlife biomonitoring in the pursuit to better understand the biology of endangered species.


Assuntos
Animais Selvagens , Ursidae , Animais , Masculino , Feminino , Humanos , Monitoramento Biológico , Espectrometria de Massas , Esteroides/análise , Cromatografia Líquida de Alta Pressão/métodos
3.
Int J Womens Health ; 16: 17-30, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38204972

RESUMO

Introduction: Alveolar soft part sarcoma (ASPS) is a rare and distinct subtype of soft tissue sarcoma. This study aims to describe the unique presentation of ASPS in the female genital tract. Methods: Prognostic factors for cancer-specific overall survival (CSS) were evaluated using multivariate analyses. Results: In our case series, we identified a novel TFE3-PRCC gene fusion in a 24-year-old unmarried patient with cervical ASPS who underwent fertility-sparing surgery and remained recurrence-free for 41 months. The other two patients underwent radical hysterectomy and bilateral salpingo-oophorectomy. At the time of writing, the two patients had been disease-free for 49 and 71 months, fluorescence in situ hybridization showed break-apart signals for the ASPL-TFE3 gene. Among the 55 cases with available information from the PubMed/Medline database, most presented with localized disease, and at the last follow-up, all patients were alive and 45 patients showed no evidence of disease. The 5-year CSS rate in the female genital tract cohort from SEER database was 86.2%. Multivariate analysis revealed that older age was associated with a 1.042-fold increased risk of cancer-specific mortality (HR=1.042, 95% CI 1.022-1.063, P < 0.001), involvement of soft tissue including the heart was associated with a 4.786-fold higher risk (HR=4.7868, 95% CI 1.681-13.623, P= 0.003), and regional infiltration and distant metastasis were associated with approximately 8.6-fold and 18-fold higher risk of cancer-specific mortality compared to local disease, respectively (HR=8.652, 95% CI 2.529-29.63, P = 0.001; HR=18.366, 95% CI 6.153-54.817, P< 0.001). Patients who underwent radical excision did not show reduced cancer-specific mortality compared to those who underwent local excision (HR=0.492, 95% CI 0.224-1.081, P = 0.078). Discussion: Previously unrecognized genetic diversity exists in ASPS. Patients with ASPS in the female genital tract have the lowest likelihood of presenting with a distant disease and are associated with a more favorable survival outcome.

4.
Small Methods ; 8(2): e2300405, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37231584

RESUMO

Bismuth-based halide perovskite materials have attracted extensive attention for optoelectronic applications due to nontoxicity and ambient stability. However, limited by low-dimensional structure and isolate octahedron arrangement, the undesirable photophysical properties of bismuth-based perovskites are still not well modulated. Here, the rational design and synthesis of Cs3 SbBiI9 with improved optoelectronic performance via premeditatedly incorporating antimony atoms with a similar electronic structure to bismuth into the host lattice of Cs3 Bi2 I9 is reported. Compared with Cs3 Bi2 I9 , the absorption spectrum of Cs3 SbBiI9 is broadened from ≈640 to ≈700 nm, the photoluminescence intensity enhances by two orders of magnitude indicating the extremely suppressed carrier nonradiative recombination, and the charge carrier lifetime is further increased from 1.3 to 207.6 ns. Taking representative applications in perovskite solar cells, the Cs3 SbBiI9 exhibits a higher photovoltaic performance benefiting from the improved intrinsic optoelectronic properties. Further structure analysis reveals that the introduced Sb atoms regulate the interlayer spacing between dimers in c-axis direction and the micro-octahedral configuration, which correlate well with the improvement of optoelectronic properties of Cs3 SbBiI9 . It is anticipated that this work will benefit the design and fabrication of lead-free perovskite semiconductors for optoelectronic applications.

5.
BMC Biol ; 21(1): 222, 2023 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-37858133

RESUMO

BACKGROUND: Energy homeostasis is essential for the adaptation of animals to their environment and some wild animals keep low metabolism adaptive to their low-nutrient dietary supply. Giant panda is such a typical low-metabolic mammal exhibiting species specialization of extremely low daily energy expenditure. It has low levels of basal metabolic rate, thyroid hormone, and physical activities, whereas the cellular bases of its low metabolic adaptation remain rarely explored. RESULTS: In this study, we generate a single-nucleus transcriptome atlas of 21 organs/tissues from a female giant panda. We focused on the central metabolic organ (liver) and dissected cellular metabolic status by cross-species comparison. Adaptive expression mode (i.e., AMPK related) was prominently displayed in the hepatocyte of giant panda. In the highest energy-consuming organ, the heart, we found a possibly optimized utilization of fatty acid. Detailed cell subtype annotation of endothelial cells showed the uterine-specific deficiency of blood vascular subclasses, indicating a potential adaptation for a low reproductive energy expenditure. CONCLUSIONS: Our findings shed light on the possible cellular basis and transcriptomic regulatory clues for the low metabolism in giant pandas and helped to understand physiological adaptation response to nutrient stress.


Assuntos
Ursidae , Animais , Feminino , Ursidae/genética , Ursidae/metabolismo , Transcriptoma , Células Endoteliais , Animais Selvagens , Exercício Físico
6.
Nanoscale ; 15(34): 13909-13931, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37581402

RESUMO

Photochemical deposition has been attracting increasing attention for preparing nano-catalysts due to its mild reaction conditions, simplicity, green and safe characteristics, and potential for various applications in photocatalysis, thermal catalysis, and electrocatalysis. In this review, we provide an overview of recent advances in photochemical deposition methods for fabricating heterogeneous catalysts, and summarize the factors that influence the nucleation and growth of metal nanoparticles during the photochemical process. Specifically, we focus on the various factors including surface defects, crystal facets, surface properties and the surface plasmon effect on the size, morphology and distribution control of metal and metal oxide nanoparticles on semiconductors. The control of the photogenerated charges and the triggered photochemical reactions have been proved to be significant in the photochemical deposition process. Besides, the applications of the obtained catalytic materials in thermal catalysis and electrocatalysis is highlighted, considering that many reviews have covered photocatalysis applications. We first introduce the principle of photodeposition, nucleation and growth theory, and factors affecting photodeposition. Then, we introduce photodeposition methods that can achieve "controlled" photodeposition from a strategic perspective. Finally, we summarize the fruitful results of controlled photodeposition and provide future prospects for the development of controlled photodeposition technologies and methods, as well as the deepening and expansion of applications.

7.
iScience ; 26(7): 107072, 2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-37534164

RESUMO

The process of heterogeneous catalytic reaction under working conditions has long been considered a "black box", which is mainly because of the difficulties in directly characterizing the structural changes of catalysts at the atomic level during catalytic reactions. The development of in situ transmission electron microscopy (TEM) techniques offers opportunities for introducing a realistic chemical reaction environment in TEM, making it possible to uncover the mystery of catalytic reactions. In this article, we present a comprehensive overview of the application of in situ TEM techniques in heterogeneous catalysis, highlighting its utility for observing gas-solid and liquid-solid reactions during thermal catalysis, electrocatalysis, and photocatalysis. in situ TEM has a unique advantage in revealing the complex structural changes of catalysts during chemical reactions. Revealing the real-time dynamic structure during reaction processes is crucial for understanding the intricate relationship between catalyst structure and its catalytic performance. Finally, we present a perspective on the future challenges and opportunities of in situ TEM in heterogeneous catalysis.

8.
mSystems ; 8(3): e0025223, 2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37273228

RESUMO

We conducted UPLC-MS-based metabolomics, 16S rRNA, and metagenome sequencing on the fecal samples of 44 captive giant pandas (Ailuropoda melanoleuca) from four age groups (i.e., Cub, Young, Adult, and Old) to comprehensively understand age-related changes in the metabolism and gut microbiota of giant pandas. We characterized the metabolite profiles of giant pandas based on 1,376 identified metabolites, with 152 significantly differential metabolites (SDMs) found across the age groups. We found that the metabolites and the composition/function of the gut microbiota changed in response to the transition from a milk-dominant diet in panda cubs to a bamboo-specific diet in young and adult pandas. Lipid metabolites such as choline and hippuric acid were enriched in the Cub group, and many plant secondary metabolites were significantly higher in the Young and Adult groups, while oxidative stress and inflammatory related metabolites were only found in the Old group. However, there was a decrease in the α-diversity of gut microbiota in adult and old pandas, who exclusively consume bamboo. The abundance of bacteria related to the digestion of cellulose-rich food, such as Firmicutes, Streptococcus, and Clostridium, significantly increased from the Cub to the Adult group, while the abundance of beneficial bacteria such as Faecalibacterium, Sarcina, and Blautia significantly decreased. Notably, several potential pathogenic bacteria had relatively high abundances, especially in the Young group. Metagenomic analysis identified 277 CAZyme genes including cellulose degrading genes, and seven of the CAZymes had abundances that significantly differed between age groups. We also identified 237 antibiotic resistance genes (ARGs) whose number and diversity increased with age. We also found a significant positive correlation between the abundance of bile acids and gut bacteria, especially Lactobacillus and Bifidobacterium. Our results from metabolome, 16S rRNA, and metagenome data highlight the important role of the gut microbiota-bile acid axis in the regulation of age-related metabolism and provide new insights into the lipid metabolism of giant pandas. IMPORTANCE The giant panda is a member of the order Carnivora but is entirely herbivorous. The giant panda's specialized diet and related metabolic mechanisms have not been fully understood. It is therefore crucial to investigate the dynamic changes in metabolites as giant pandas grow and physiologically adapt to their herbivorous diet. This study conducted UPLC-MS-based metabolomics 16S rRNA, and metagenome sequencing on the fecal samples of captive giant pandas from four age groups. We found that metabolites and the composition/function of gut microbiota changed in response to the transition from a milk-dominant diet in cubs to a bamboo-specific diet in young and adult pandas. The metabolome, 16S rRNA, and metagenome results highlight that the gut microbiota-bile acid axis has an important role in the regulation of age-related metabolism, and our study provides new insights into the lipid metabolism of giant pandas.


Assuntos
Carnívoros , Microbiota , Ursidae , Animais , Ursidae/genética , RNA Ribossômico 16S/genética , Cromatografia Líquida , Espectrometria de Massas em Tandem , Carnívoros/genética , Metaboloma , Dieta , Bactérias/genética , Celulose/metabolismo
9.
Adv Mater ; 35(29): e2300914, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37038704

RESUMO

Although modulating oxygen vacancies in semiconductors has attracted broad interest in photocatalysis and photoelectrocatalysis, identifying the intrinsic roles of oxygen vacancies on photoelectrocatalytic properties is often elusive. In this work, the oxygen vacancies in a typical semiconductor lead chromate (PbCrO4 ) are regulated via controlling the oxygen chemical potentials of O-poor and O-rich post-annealing atmospheres. Oxygen vacancies identified in PbCrO4 can introduce electronically shallow energy levels and deep energy levels owing to the symmetry difference of oxygen atoms in the structure. A higher population of deep energy levels created under O-poor atmosphere induces the formation of more surface trapped states, resulting in a higher photovoltage for charge separation. Meanwhile, the existence of surface trapped states can significantly improve the charge injection efficiency of the PbCrO4 photoanode and enhance the water oxidation activity. By modulating oxygen vacancies in the PbCrO4 photoanode, a photocurrent density of 3.43 mA cm-2 at 1.23 V vs reversible hydrogen electrode (RHE) under simulated AM1.5G is acheived. Further passivation of surface trapped states and introducing the water oxidation cocatalyst CoPi lead to a record applied bias photon-to-current efficiency (ABPE) of 1.12%. This work provides a guide to understand the mechanism of oxygen vacancies in oxide-based semiconductor photocatalysis and photoelectrocatalysis.

10.
Angew Chem Int Ed Engl ; 62(21): e202302575, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36959093

RESUMO

The interfacial barrier of charge transfer from semiconductors to cocatalysts means that the photogenerated charges cannot be fully utilized, especially for the challenging water oxidation reaction. Using cobalt cubane molecules (Co4 O4 ) as water oxidation cocatalysts, we rationally assembled partially oxidized graphene (pGO), acting as a charge-transfer mediator, on the hole-accumulating {-101} facets of lead chromate (PbCrO4 ) crystal. The assembled pGO enables preferable immobilization of Co4 O4 molecules on the {-101} facets of the PbCrO4 crystal, which is favorable for the photogenerated holes transferring from PbCrO4 to Co4 O4 molecules. The surface charge-transfer efficiency of PbCrO4 was boosted by selective assembly of pGO between PbCrO4 and Co4 O4 molecules. An apparent quantum efficiency for photocatalytic water oxidation on the Co4 O4 /pGO/PbCrO4 photocatalyst exceeded 10 % at 500 nm. This strategy of rationally assembling charge-transfer mediator provides a feasible method for acceleration of charge transfer and utilization in semiconductor photocatalysis.

11.
Adv Mater ; 35(15): e2211182, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36779436

RESUMO

Photocatalytic water splitting for solar energy conversion remains challenged by the lack of novel semiconductor photocatalysts with paramount parameters including wide light-harvesting ranges and suitable band structures. Here, a novel triclinic-phase bismuth chromate (Bi2 CrO6 ) acting as a semiconductor photocatalyst candidate is reported. Triclinic Bi2 CrO6 exhibits a broad absorption range of ≈650 nm with a direct bandgap of 1.86 eV and shows a suitable band structure for water splitting. Theoretical simulations of triclinic Bi2 CrO6 reveal a high charge mobility, possibly owing to the strong hybridized covalent bonds, large elastic modulus, and small carrier effective mass. The triclinic Bi2 CrO6 is demonstrated to work well toward photocatalytic water oxidation and hydrogen production reactions under visible light and match well with its absorption ranges. In particular, it exhibits decent photocatalytic water oxidation performance in the presence of various electron scavengers. Furthermore, the visible-light-driven Z-scheme overall water splitting system is fabricated by coupling triclinic Bi2 CrO6 as the oxygen evolution photocatalyst with SrTiO3 :Rh as the hydrogen evolution photocatalyst, giving a stable overall water splitting with stoichiometric evolution of H2 and O2 . This work presents a promising semiconductor material enabling wide-range light harvesting for photocatalytic and photo-electrochemical solar energy conversion.

12.
Front Oncol ; 12: 1028842, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36425559

RESUMO

Objective: To determine the effect of adjuvant chemotherapy in patients with stage I mucinous ovarian cancer (MOC) undergoing fertility-preserving surgery. Patients and methods: The clinicopathological characteristics and survival information of young women with stage I MOC from SEER databases between 2004 and 2019 were collected. The relationship between chemotherapy and the characteristics was examined by univariate and multivariate logistic regression analyses. Univariable and multivariate Cox proportional hazards survival analysis were employed for cancer-specific survival. Cox analysis was performed to build a nomogram model. Results: All 901 eligible patients with stage I MOC were screened from the SEER database. There were 321(35.6%) patients aged 9-30 years, 580(64.4%) aged 31-45 years, 645 (71.6%) patients with stage IA/IB, 256 (28.4%) with stage IC disease, 411(45.6%) who underwent fertility-sparing surgery, and276(30.6%) who received postoperative adjuvant chemotherapy. Multivariate logistic regression analyses showed that postoperative chemotherapy was often used in patients aged 31-45 relative to aged 9-30 (HR: 2.215, 95%CI 1.443-3.401, P < 0.001) or with grade 3 compared to grade 1 tumors (HR: 7.382, 95%CI 4.054-13.443, P < 0.001) or with stage IC compared to stage IA/IB (HR: 6.436, 95%CI 4.515-9.175, P < 0.001) or with non-fertility sparing surgery relative to fertility-sparing (HR:2.226, 95%CI 1.490-3.327, P < 0.001). Multivariate analysis for the special population with fertility preservation indicated that patients with chemotherapy (HR: 2.905, 95% CI: 0.938-6.030, P=0.068) or with grade 3 (HR: 4.750, 95% CI: 1.419-15.896, P=0.011) had a greater risk of mortality. Significant CSS differences were observed between the non-chemotherapy and chemotherapy groups in MOC when patients were stage IA/IB-grade 2 (P=0.004) (10-year CSS rates of chemotherapy=84%, non-chemotherapy = 100%), but not when they were stage IA/IB-grade 1, stage IA/IB-grade 3 or stage IC (both P>0.05). A prognostic prediction nomogram model was built for stage I MOC patient who underwent fertility-sparing and the C-index was 0.709. Discussion: The patients aged 31-45 years, with grade 3, stage IC, and non-fertility-sparing surgery were more likely to receive adjuvant chemotherapy in the real world. For stage I MOC patient who underwent fertility-sparing surgery, the choice of chemotherapy may increase the risk of death, and it should be carefully selected in clinical practice.

13.
Chem Soc Rev ; 51(24): 10120-10122, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36448635

RESUMO

Correction for 'Recent advances and perspectives for solar-driven water splitting using particulate photocatalysts' by Xiaoping Tao et al., Chem. Soc. Rev., 2022, 51, 3561-3608, https://doi.org/10.1039/d1cs01182k.

14.
Chemistry ; 28(66): e202202007, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36163587

RESUMO

Efficient separation of photogenerated electrons and holes is of key importance in photocatalysis. Tuning the charge separation pathway is significant but still suffering from low efficiency for the charge extraction from semiconductors. Herein, taking 2D g-C3 N4 (CN) nanosheets as a model photocatalyst, it was found the decoration of homophase junction between brookite TiO2 rods and nanoparticles (BN -BR ) onto CN can effectively modulate photogenerated charge extraction and transfer in BN -BR /CN composites. The BN -BR /CN exhibits a remarkably enhanced photocatalytic H2 evolution under visible light irradiation (λ>420 nm) compared with the single component. A continuous electron transfer channel constructed by an interfacial chemical bond Ti-O-N between CN and brookite rods (BR ) and BN -BR homophase junction between brookite nanoparticles and rods was proposed to benefit the charge extraction and transfer. This work provides a strategy to tune the charge separation and transfer to facilitate the photocatalytic performance in heterogeneous photocatalysis.

15.
Adv Mater ; 34(37): e2203320, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35916758

RESUMO

Titanium dioxide (TiO2 ) nanocrystals have attracted great attention in heterogeneous photocatalysis and photoelectricity fields for decades. However, contradicting conclusions on the crystallographic orientation and exposed facets of TiO2 nanocrystals frequently appear in the literature. Herein, using anatase TiO2 nanocrystals with highly exposed {001} facets as a model, the misleading conclusions that exist on anatase nanocrystals are clarified. Although TiO2 -001 nanocrystals are recognized to be dominated by {001} facets, in fact, anatase nanocrystals with both dominant {001} and {111} facets always co-exist due to the similarities in the lattice fringes and intersection angles between the two types of facets (0.38 nm and 90° in the [001] direction, 0.35 nm and 82° in the [111] direction). A paradigm for determining the crystallographic orientation and exposed facets based on transmission electron microscopy (TEM) analysis, which provides a universal methodology to nanomaterials for determining the orientation and exposed facets, is also given.

16.
Reprod Fertil ; 3(3): 122-132, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35949393

RESUMO

Abstract: Giant pandas are mono-estrus seasonal breeders, with the breeding season typically occurring in the spring. Successful fertilization is followed by an embryonic diapause, of variable length, with birth in the late summer/autumn. There is a need for additional understanding of giant panda reproductive physiology, and the development of enhanced biomarkers for impending proestrus and peak fertility. We aimed to determine the utility of non-invasive androgen measurements in the detection of both proestrus and estrus. Urine from 20 cycles (-40 days to +10 days from peak estrus) from 5 female giant pandas was analyzed for estrogen, progestogens and androgens (via testosterone and DHEA assays), and hormone concentrations were corrected against urinary specific gravity. Across proestrus, estrogens increased while progestogens and androgens decreased - at the point of entry into proestrus, androgens (as detected by the testosterone assay) decreased prior to progestogens and gave 4 days advanced warning of proestrus. At the time of peak estrus, androgens (as detected by the DHEA assay) were significantly increased at the time of the decrease in estrogen metabolites from the peak, acting as an alternative confirmatory indicator of the fertile window. This novel finding allows for enlargement of the preparative window for captive breeding and facilitates panda management within breeding programmes. Androgens allow an enhanced monitoring of giant panda estrus, not only advancing the warning of impending proestrus, but also prospectively identifying peak fertility. Lay summary: Giant pandas have one chance at pregnancy per year. The 2-day fertile window timing varies by year and panda. This is monitored by measuring the level of estrogens in the urine, which increase, indicating an upcoming fertile period. After 1-2 weeks of increase, estrogens peak and fall, marking the optimal fertile time. We tested other hormones to see if we can predict the fertile window in advance, and the specific fertile time with more accuracy. In 20 breeding seasons from 5 females, we found androgens, usually thought of as male hormones, had an important role. Testosterone gives 4 days advanced warning of estrogens increasing. DHEA identified peak estrogen and the fertile time before needing to see a confirmed decrease in estrogen itself. Therefore, androgens help improve monitoring of the giant panda breeding season, giving early warning of fertility, key in facilitating captive breeding and giant panda conservation.


Assuntos
Ursidae , Androgênios , Animais , Desidroepiandrosterona , Estrogênios , Feminino , Fertilidade , Masculino , Melhoramento Vegetal , Gravidez , Progestinas , Testosterona
17.
Angew Chem Int Ed Engl ; 61(37): e202207161, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-35716112

RESUMO

A crucial issue in artificial photosynthesis is how to modulate the behaviors of photogenerated charges of semiconductor photocatalysts. Here, using lead chromate (PbCrO4 ) as an example, we conducted the morphology tailoring from parallelepiped (p-PbCrO4 ) to truncated decahedron (t-PbCrO4 ) and elongated rhombic (r-PbCrO4 ), resulting in exposed anisotropic facets. The spatial separation of photogenerated charges closely correlates to the anisotropic facets of crystals, which can only be realized for t-PbCrO4 and r-PbCrO4 . The charge-separation efficiencies exhibit a quasilinear relation with the surface photovoltage difference between anisotropic facets. The r-PbCrO4 gives an apparent quantum efficiency of 6.5 % at 500 nm for photocatalytic water oxidation using Fe3+ ions as electron acceptors. Moreover, the oxidation reverse reaction from Fe2+ to Fe3+ ions was completely blocked with ∼100 % of Fe3+ conversion achieved on the anisotropic PbCrO4 crystals.

18.
Mol Biol Rep ; 49(6): 4901-4908, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35534585

RESUMO

BACKGROUND: Research on genetic diversity based on mitochondrial DNA of giant pandas mainly focused on a single marker or a few genes. OBJECTIVE: To provide a more comprehensive assessment of the genetic diversity on giant pandas based on 13 mitochondrial protein coding genes. METHODS: We assembled 13 protein coding genes in the mitochondrial genome of the giant panda based on the whole genome sequencing data, including ND1, ND2, COX1, COX2, ATP8, ATP6, COX3, ND3, ND4L, ND4, ND5, ND6 and Cyt b. RESULTS: We successfully obtained long sequence of 11,416 base pairs with all 13 genes for 110 giant panda individual, accounting for 67.93% in length of the mitochondrial reference genome. Haplotype diversity was 0.9518 ± 0.009 and nucleotide diversity (π) was 0.00157 ± 0.00014. We detected three new haplotypes, including GPC10 and GPC21 for the CR sequence and GPB12 for the Cyt b gene. CONCLUSION: These multi-gene sequences provided more genetic variable information to compare captive and wild giant panda population.


Assuntos
Genoma Mitocondrial , Ursidae , Animais , Composição de Bases , Citocromos b/genética , DNA Mitocondrial/genética , Genes Mitocondriais/genética , Genoma Mitocondrial/genética , Análise de Sequência de DNA , Ursidae/genética
19.
Adv Mater ; 34(29): e2110610, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35589018

RESUMO

Photoelectrochemical (PEC) water splitting for renewable hydrogen production has been regarded as a promising solution to utilize solar energy. However, most photoelectrodes still suffer from poor film quality and poor charge separation properties, mainly owing to the possible formation of detrimental defects including microcracks and grain boundaries. Herein, a molecular coordination engineering strategy is developed by employing acetylacetone (Acac) and poly(ethylene glycol) (PEG) dual ligands to regulate the nucleation and crystal growth of the lead chromate (PbCrO4 ) photoanode, resulting in the formation of a high-quality film with large grain size, well-stitched grain boundaries, and reduced oxygen vacancies defects. With these efforts, the nonradiative charge recombination is efficiently suppressed, leading to the enhancement of its charge separation efficiency from 47% to 90%. After decorating with Co-Pi cocatalyst, the PbCrO4 photoanode achieves a photocurrent density of 3.15 mA cm-2 at 1.23 V (vs RHE under simulated AM1.5G) and an applied bias photon-to-current efficiency (ABPE) of 0.82%. This work provides a new strategy to modulate the nucleation and growth of high-quality photoelectrodes for efficient PEC water splitting.

20.
Nat Commun ; 13(1): 2648, 2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35551203

RESUMO

Semi-hydrogenation of acetylene in excess ethylene is a key industrial process for ethylene purification. Supported Pd catalysts have attracted most attention due to their superior intrinsic activity but often suffer from low selectivity. Pd single-atom catalysts (SACs) are promising to significantly improve the selectivity, but the activity needs to be improved and the feasible preparation of Pd SACs remains a grand challenge. Here, we report a simple strategy to construct Pd1/TiO2 SACs by selectively encapsulating the co-existed small amount of Pd nanoclusters/nanoparticles based on their different strong metal-support interaction (SMSI) occurrence conditions. In addition, photo-thermo catalysis has been applied to this process where a much-improved catalytic activity was obtained. Detailed characterization combined with DFT calculation suggests that photo-induced electrons transferred from TiO2 to the adjacent Pd atoms facilitate the activation of acetylene. This work offers an opportunity to develop highly stable Pd SACs for efficient catalytic semi-hydrogenation process.

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