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1.
BMC Genomics ; 25(1): 385, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38641598

RESUMO

BACKGROUND: The C2H2 zinc finger protein family plays important roles in plants. However, precisely how C2H2s function in Opisthopappus (Opisthopappus taihangensis and Opisthopappus longilobus) remains unclear. RESULTS: In this study, a total of 69 OpC2H2 zinc finger protein genes were identified and clustered into five Groups. Seven tandem and ten fragment repeats were found in OpC2H2s, which underwent robust purifying selection. Of the identified motifs, motif 1 was present in all OpC2H2s and conserved at important binding sites. Most OpC2H2s possessed few introns and exons that could rapidly activate and react when faced with stress. The OpC2H2 promoter sequences mainly contained diverse regulatory elements, such as ARE, ABRE, and LTR. Under salt stress, two up-regulated OpC2H2s (OpC2H2-1 and OpC2H2-14) genes and one down-regulated OpC2H2 gene (OpC2H2-7) might serve as key transcription factors through the ABA and JA signaling pathways to regulate the growth and development of Opisthopappus species. CONCLUSION: The above results not only help to understand the function of C2H2 gene family but also drive progress in genetic improvement for the salt tolerance of Opisthopappus species.


Assuntos
Dedos de Zinco CYS2-HIS2 , Dedos de Zinco CYS2-HIS2/genética , Estresse Salino/genética , Genoma de Planta , Fatores de Transcrição/metabolismo , Dedos de Zinco/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Filogenia
2.
Small ; : e2401487, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38767498

RESUMO

Reducing the defect density of perovskite films during the crystallization process is critical in preparing high-performance perovskite solar cells (PSCs). Here, a multi-functional molecule, 3-phenyl-4-aminobutyric acid hydrochloride (APH), with three functional groups including a benzene ring, ─NH3 + and ─COOH, is added into the perovskite precursor solution to improve perovskite crystallization and device performance. The benzene ring increases the hydrophobicity of perovskites, while ─NH3 + and ─COOH passivate defects related to I- and Pb2+, respectively. Consequently, the power conversion efficiency (PCE) of the optimal device increased to 24.65%. Additionally, an effective area of 1 cm2 with a PCE of 22.45% is also prepared using APH as an additive. Furthermore, PSCs prepared with APH exhibit excellent stability by 87% initial PCE without encapsulation after exposure at room temperature under 25% humidity for 5000 h and retaining 70% of initial PCE after aging at 85 °C in an N2 environment for 864 h.

3.
Phys Rev Lett ; 132(5): 056301, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38364160

RESUMO

Recent experiments reported an antisymmetric planar Hall effect, where the Hall current is odd in the in plane magnetic field and scales linearly with both electric and magnetic fields applied. Existing theories rely exclusively on a spin origin, which requires spin-orbit coupling to take effect. Here, we develop a general theory for the intrinsic planar Hall effect (IPHE), highlighting a previously unknown orbital mechanism and connecting it to a band geometric quantity-the anomalous orbital polarizability (AOP). Importantly, the orbital mechanism does not request spin-orbit coupling, so sizable IPHE can occur and is dominated by an orbital contribution in systems with weak spin-orbit coupling. Combined with first-principles calculations, we demonstrate our theory with quantitative evaluation for bulk materials TaSb_{2}, NbAs_{2}, and SrAs_{3}. We further show that AOP and its associated orbital IPHE can be greatly enhanced at topological band crossings, offering a new way to probe topological materials.

4.
Phys Rev Lett ; 130(12): 126303, 2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-37027844

RESUMO

We propose an intrinsic nonlinear planar Hall effect, which is of band geometric origin, independent of scattering, and scales with the second order of electric field and first order of magnetic field. We show that this effect is less symmetry constrained compared with other nonlinear transport effects and is supported in a large class of nonmagnetic polar and chiral crystals. Its characteristic angular dependence provides an effective way to control the nonlinear output. Combined with first-principles calculations, we evaluate this effect in the Janus monolayer MoSSe and report experimentally measurable results. Our work reveals an intrinsic transport effect, which offers a new tool for material characterization and a new mechanism for nonlinear device application.

5.
Phys Rev Lett ; 130(16): 166302, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37154629

RESUMO

We propose a time-reversal-even spin generation in second order of electric fields, which dominates the current induced spin polarization in a wide class of centrosymmetric nonmagnetic materials, and leads to a novel nonlinear spin-orbit torque in magnets. We reveal a quantum origin of this effect from the momentum space dipole of the anomalous spin polarizability. First-principles calculations predict sizable spin generations in several nonmagnetic hcp metals, in monolayer TiTe_{2}, and in ferromagnetic monolayer MnSe_{2}, which can be detected in experiment. Our work opens up the broad vista of nonlinear spintronics in both nonmagnetic and magnetic systems.

6.
BMC Biol ; 20(1): 281, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36522765

RESUMO

BACKGROUND: Sex differences ranging from physiological functions to pathological disorders are developmentally hard-wired in a broad range of animals, from invertebrates to humans. These differences ensure that animals can display appropriate behaviors under a variety of circumstances, such as aggression, hunting, sleep, mating, and parental care, which are often thought to be important in the acquisition of resources, including territory, food, and mates. Although there are reports of an absence of sexual dimorphism in the context of innate fear, the question of whether there is sexual dimorphism of innate defensive behavior is still an open question. Therefore, an in-depth investigation to determine whether there are sex differences in developmentally hard-wired innate defensive behaviors in life-threatening circumstances is warranted. RESULTS: We found that innate defensive behavioral responses to potentially life-threatening stimuli between males and females were indistinguishable over their lifespan. However, by using 3 dimensional (3D)-motion learning framework analysis, we found that males and females showed different behavioral patterns after escaping to the refuge. Specifically, the defensive "freezing" occurred primarily in males, whereas females were more likely to return directly to exploration. Moreover, there were also no estrous phase differences in innate defensive behavioral responses after looming stimuli. CONCLUSIONS: Our results demonstrate that visually-evoked innate fear behavior is highly conserved throughout the lifespan in both males and females, while specific post-threat coping strategies depend on sex. These findings indicate that innate fear behavior is essential to both sexes and as such, there are no evolutionary-driven sex differences in defensive ability.


Assuntos
Sinais (Psicologia) , Medo , Humanos , Camundongos , Feminino , Masculino , Animais , Medo/fisiologia , Instinto , Caracteres Sexuais , Adaptação Psicológica
7.
J Environ Manage ; 327: 116861, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36442446

RESUMO

Overgrazing has become one of the main factors affecting grassland degradation over the past two decades in China. To solve this problem, the government has implemented a grassland ecological compensation policy and grazing monitoring system that is highly dependent on rural cadres. However, few studies have analyzed the impact of political status (rural cadres' identity) on overgrazing. This study reveals the impact of political status on herders' overgrazing behavior. It evaluates the moderating effect of social capital on this impact using a linear regression model based on survey data from 640 herder households in Inner Mongolia, Gansu, and Qinghai, China. The results show that herders with political status are more likely to overgraze. The level of trust in rural cadres has a positive moderating effect on the influence of political status on herders' overgrazing. Small farms with political status are more likely to overgraze compared to large farms. Grazing monitoring by local government can reduce the overgrazing of herders with political status and weaken the positive effects of political status and the trust level in rural cadres regarding overgrazing. Therefore, local governments should monitor more strictly grazing activities for herders with political status, especially those with small grassland scales, and pay more attention to the role of herders' social capital in constructing a sustainable grassland governance mechanism.


Assuntos
Política , Capital Social , Humanos , China , População Rural
8.
Angew Chem Int Ed Engl ; 62(30): e202305815, 2023 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-37227157

RESUMO

Halide-related surface defects on inorganic halide perovskite not only induce charge recombination but also severely limit the long-term stability of perovskite solar cells. Herein, adopting density functional theory calculation, we verify that iodine interstitials (Ii ) has a low formation energy similar to that of the iodine vacancy (VI ) and is also readily formed on the surface of all-inorganic perovskite, and it is regarded to function as an electron trap. We screen a specific 2,6-diaminopyridine (2,6-DAPy) passivator, which, with the aid of the combined effects from halogen-Npyridine and coordination bonds, not only successfully eliminates the Ii and dissociative I2 but also passivates the abundant VI . Furthermore, the two symmetric neighboring -NH2 groups interact with adjacent halides of the octahedral cluster by forming hydrogen bonds, which further promotes the adsorption of 2,6-DAPy molecules onto the perovskite surface. Such synergetic effects can significantly passivate harmful iodine-related defects and undercoordinated Pb2+ , prolong carrier lifetimes and facilitate the interfacial hole transfer. Consequently, these merits enhance the power-conversion efficiency (PCE) from 19.6 % to 21.8 %, the highest value for this type of solar cells, just as importantly, the 2,6-DAPy-treated CsPbI3-x Brx films show better environmental stability.

9.
Medicina (Kaunas) ; 58(12)2022 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-36557006

RESUMO

Esophageal submucosal tumors are rare, but their pathological types are diverse. In addition to the relatively common leiomyomas, some rare submucosal lesions are occasionally reported. Waldeyer's ring is described as a unique subtype of mucosa-associated lymphoid tissue, located in the naso-oropharynx. Studies have reported that Waldeyer's ring is the most common site of primary extranodal lymphoma in the head and neck. Interestingly, we encountered an esophageal submucosal tumor-like lesion similar to the tonsillar structures of Waldeyer's ring. A 38-year-old man underwent esophagoscopy after experiencing swallowing discomfort for 3 months. A protruding submucosal mass with slightly rough mucosa was found at the cervical esophagus approximately 20 cm from the incisors. Considering the possibility of the coexistence of a submucosal tumor and a mucosal lesion, as well as the continuous symptoms of swallowing discomfort, the patient underwent endoscopic submucosal dissection. The lesion was removed en bloc. However, histology revealed a lesion similar to the tonsillar structure of Waldeyer's ring between the lamina propria and submucosa. The patient was followed up for 6 months without recurrence or complaints. We report a new submucosal lesion and discuss its origin and treatment. Diagnostic ESD might be an effective option until its malignant potential is clarified.


Assuntos
Neoplasias Esofágicas , Neoplasias Tonsilares , Masculino , Humanos , Adulto , Neoplasias Tonsilares/patologia , Pescoço , Neoplasias Esofágicas/cirurgia , Mucosa
10.
Int J Neuropsychopharmacol ; 23(3): 181-191, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-31990032

RESUMO

BACKGROUND: Both the clinical and preclinical studies have suggested embryonic or infant exposure to ketamine, a general anesthetic, pose a great threat to the developing brain. However, it remains unclear how ketamine may contribute to the brain dysfunctions. METHODS: A mouse model of prenatal exposure to ketamine was generated by i.m. injection and continuous i.p. infusion of pregnant mice. Open field test and elevated plus maze test were used to analyze the behavioral alterations induced by ketamine. Immunostaining by c-Fos was used to map the neuron activity. Chemogenetic modulation of the neurons was used to rescue the abnormal neuron activity and behaviors. RESULTS: Here we show that mice prenatally exposed to ketamine displayed anxiety-like behaviors during adulthood, but not during puberty. C-Fos immunostaining identified abnormal neuronal activity in Bed Nucleus of the Stria Terminalis, the silencing of which by chemogenetics restores the anxiety-like behaviors. CONCLUSIONS: Taken together, these results demonstrate a circuitry mechanism of ketamine-induced anxiety-like behaviors.


Assuntos
Anestésicos Dissociativos/farmacologia , Ansiedade/induzido quimicamente , Ketamina/farmacologia , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Núcleos Septais/efeitos dos fármacos , Fatores Etários , Anestésicos Dissociativos/administração & dosagem , Animais , Ansiedade/fisiopatologia , Comportamento Animal/fisiologia , Modelos Animais de Doenças , Feminino , Técnicas Genéticas , Ketamina/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Maturidade Sexual/fisiologia
11.
Phys Rev Lett ; 125(14): 143001, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33064518

RESUMO

Unconventional Weyl points (WPs), carrying topological charge 2 or higher, possess interesting properties different from ordinary charge-1 WPs, including multiple Fermi arcs that stretch over a large portion of the Brillouin zone. Thus far, such WPs have been observed in chiral materials and acoustic metamaterials, but there has been no clean demonstration in photonics in which the unconventional photonic WPs are separated from trivial bands. We experimentally realize an ideal symmetry-protected photonic charge-2 WP in a three-dimensional topological chiral microwave metamaterial. We use field mapping to directly observe the projected bulk dispersion, as well as the two long surface arcs that form a noncontractible loop wrapping around the surface Brillouin zone. The surface states span a record-wide frequency window of around 22.7% relative bandwidth. We demonstrate that the surface states exhibit a novel topological self-collimation property and are robust against disorder. This work provides an ideal photonic platform for exploring fundamental physics and applications of unconventional WPs.

12.
Phys Chem Chem Phys ; 20(3): 1560-1567, 2018 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-29260153

RESUMO

We propose a graphene device that can generate spin-dependent negative differential resistance (NDR). The device is composed of a sufficiently wide and short graphene sheet and two gated EuO strips deposited on top of it. This scheme avoids the graphene edge tailoring required by previous proposals. More importantly, we find a clear indication of a spin selectivity and a region tunability in the spin-dependent NDR: by changing the top gates of the device, NDR for spin up only, spin down only, or both spins (occurring sequentially) can be respectively realized; meanwhile, the central position of the NDR region in each case can be monotonously tuned over a wide range of bias voltage. These remarkable features are attributed to a gate controllability of the spin-dependent resonance levels in the device hence their deviations from the Fermi energy and the Dirac point in the source electrode respectively. They add a spin and a bias degree of freedom to the conventional NDR, which paves the way for designing a whole new class of NDR circuits.

13.
Breast Cancer Res Treat ; 149(2): 395-401, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25534827

RESUMO

We determined c-kit expression in the stroma and epithelia of benign, borderline, and malignant phyllodes tumors (PTs), respectively, as well as the relationship between c-kit expression in stromal elements and KIT gene copy number variations (CNVs). To assess c-kit expression and KIT CNVs, 348 PT cases were studied: 120 (34.4 %) benign cases, 115 (33.1 %) borderline cases, and 113 (32.5 %) malignant cases. All of these cases were evaluated for c-kit (CD117) expression using immunohistochemistry. Forty-two cases (29 c-kit-positive in the stromal cells cases and 13 negative cases) were investigated for KIT gene CNVs via genomic polymerase chain reaction (PCR). The overall rate of c-kit positivity in the stroma was 46.8 %, as well as 24.2, 53.1, and 64.6 %, respectively, in PTs of three different grades. However, in the majority of cases, the epithelia were c-kit positive (98.2 %), and the positivity was 100, 99.1, and 95 % in PTs of three different grades, respectively. There was a significant change in the expression of c-kit in the stroma and epithelia according to grade (P < 0.001, P = 0.014). From the genomic PCR results, we can confirm that c-kit positivity in the stroma is directly correlated with KIT gene copy numbers increases (P = 0.003, P = 0.041). We demonstrated that c-kit expression in the stroma of PTs is positively associated with malignancy. c-Kit epithelial positivity was inversely correlated with PTs malignancy. c-Kit overexpression in the stroma was related to KIT gene copy numbers increases.


Assuntos
Neoplasias da Mama/genética , Dosagem de Genes , Expressão Gênica , Tumor Filoide/genética , Proteínas Proto-Oncogênicas c-kit/genética , Adolescente , Adulto , Idoso , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Criança , Variações do Número de Cópias de DNA , Éxons , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Gradação de Tumores , Tumor Filoide/metabolismo , Tumor Filoide/patologia , Reação em Cadeia da Polimerase , Adulto Jovem
14.
J Surg Oncol ; 112(6): 569-74, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26458282

RESUMO

BACKGROUND AND OBJECTIVES: There is a paucity of data examining whether 1-3 positive lymph nodes patients have similar survival outcomes. The present studies separately analyse survival outcomes of T1-2N1 breast cancer patients according to the number of positive lymph nodes. METHODS: A total of 1,030 patients with T1-2N1 breast cancer were available for analysis. Survival estimates were calculated using the Kaplan-Meier method, univariate, and multivariate logistic regression models RESULTS: Kaplan-Meier analysis showed progressively worse survival with the increased number of positive lymph nodes. Log-rank test P values were 0.003 (1 vs. 2 positive LNs), <0.0001 (1 vs. 3), and 0.006 (2 vs. 3) for recurrence-free survival (RFS). Log-rank test P values were 0.045 (1 vs. 2), <0.0001 (1 vs. 3), and 0.018 (2 vs. 3) for metastasis-free survival (MFS). Log-rank test P values were 0.101 (1 vs. 2), <0.0001 (1 vs. 3), and 0.005 (2 vs. 3) for overall survival (OS). Multivariate analysis showed that 3 and 2 positive lymph nodes had worse survival compared with 1 positive axillary lymph nodes. CONCLUSIONS: Our study does suggest that T1-2N1 patients showed progressively worse survival outcomes with the increased number of positive lymph nodes.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Linfonodos/patologia , Mastectomia/mortalidade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/cirurgia , Feminino , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Pessoa de Meia-Idade , Gradação de Tumores , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/cirurgia , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Carga Tumoral , Adulto Jovem
15.
Polymers (Basel) ; 16(4)2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-38399919

RESUMO

The emergence of novel e-textile materials that combine the inherent qualities of the textile substrate (lightweight, soft, breathable, durable, etc.) with the functionality of micro/nano-electronic materials (conductive, dielectric, sensing, etc.) has resulted in a trend toward miniaturization, integration, and intelligence in new electronic devices. However, the formation of a conductive network by micro/nano-conductive materials on textiles necessitates high-temperature sintering, which inevitably causes substrate aging and component damage. Herein, a bis-hydroxy-imidazolium chloride salt as a hard segment to synthesize a waterborne polyurethane (WPU) adhesive is designed and prepared. When used in nano-silver-based printing coatings, it offers strong adherence for coatings, reaching 16 N cm-1; on the other hand, the introduction of chloride ions enables low-temperature (60 °C) chemical sintering to address the challenge of secondary treatment and high-temperature sintering (>150 °C). Printed into flexible circuits, the resistivity can be controlled by the content of imidazolium salts anchored in the molecular chain of the WPU from a maximum resistivity of 3.1 × 107 down to 5.8 × 10-5 Ω m, and it can conduct a Bluetooth-type finger pulse detector with such low resistivity. As a flexible circuit, it also offers high stability against washing and adhesion, which the resistivity only reduces less than 20% after washing 10 times and adhesion. Owing to the adjustability of the resistivity, we fabricated an all-textile flexible pressure sensor that accurately differentiates different external pressures (min. 10 g, ~29 Pa), recognizes forms, and detects joint motions (finger bending and wrist flexion).

16.
Artigo em Inglês | MEDLINE | ID: mdl-38961051

RESUMO

Thick polycrystalline perovskite films synthesized by using solution processes show great potential in X-ray detection applications. However, due to the evaporation of the solvent, many pinholes and defects appear in the thick films, which deteriorate their optoelectronic properties and diminish their X-ray detection performance. Therefore, the preparation of large area and dense perovskite thick films is desired. Herein, we propose an effective strategy of filling the pores with a saturated precursor solution. By adding the saturated perovskite solution to the polycrystalline perovskite thick film, the original perovskite film will not be destroyed because of the solution-solute equilibrium relationship. Instead, it promotes in situ crystal growth within the thick film during the annealing process. The loosely packed grains in the original thick perovskite film are connected, and the pores and defects are partially filled and fixed. Finally, a much denser perovskite thick film with improved optoelectronic properties has been obtained. The optimized thick film exhibits an X-ray sensitivity of 1616.01 µC Gyair-1 cm-2 under an electric field of 44.44 V mm-1 and a low detection limit of 28.64 nGyair s-1 under an electric field of 22.22 V mm-1. These values exceed the 323.86 µC Gyair-1 cm-2 and 40.52 nGyair s-1 of the pristine perovskite thick film measured under the same conditions. The optimized thick film also shows promising working stability and X-ray imaging capability.

17.
Plants (Basel) ; 13(4)2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38498538

RESUMO

When plants are exposed to salt stress, endogenous hormones are essential for their responses through biosynthesis and signal transduction pathways. However, the roles of endogenous hormones in two cliff species (Opisthopappus taihangensis and Opisthopappus longilobus (Opisthopappus genus)) in the Taihang Mountains under salt stress have not been investigated to date. Following different time treatments under 500 mM salt concentrations, 239 differentially expressed gene (DEG)-related endogenous hormones were identified that exhibited four change trends, which in Profile 47 were upregulated in both species. The C-DEG genes of AUX, GA, JA, BR, ETH, and ABA endogenous hormones were significantly enriched in Opisthopappus taihangensis (O. taihangensis) and Opisthopappus longilobus (O. longilobus). During the responsive process, mainly AUX, GA, and JA biosynthesis and signal transduction were triggered in the two species. Subsequently, crosstalk further influenced BR, EHT, ABA, and MAPK signal transduction pathways to improve the salt resistance of the two species. Within the protein-protein interactions (PPI), seven proteins exhibited the highest interactions, which primarily involved two downregulated genes (SAUR and GA3ox) and eight upregulated genes (ACX, MFP2, JAZ, BRI1, BAK1, ETR, EIN2, and SNRK2) of the above pathways. The more upregulated expression of ZEP (in the ABA biosynthesis pathway), DELLA (in the GA signaling pathway), ABF (in the ABA signaling pathway), and ERF1 (in the ETH signaling pathway) in O. taihangensis revealed that it had a relatively higher salt resistance than O. longilobus. This revealed that the responsive patterns to salt stress between the two species had both similarities and differences. The results of this investigation shed light on the potential adaptive mechanisms of O. taihangensis and O. longilobus under cliff environments, while laying a foundation for the study of other cliff species in the Taihang Mountains.

18.
Plants (Basel) ; 13(10)2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38794406

RESUMO

Disentangling how climate oscillations and geographical events significantly influence plants' genetic architecture and demographic history is a central topic in phytogeography. The deciduous ancient tree species Ulmus macrocarpa is primarily distributed throughout Northern China and has timber and horticultural value. In the current study, we studied the phylogenic architecture and demographical history of U. macrocarpa using chloroplast DNA with ecological niche modeling. The results indicated that the populations' genetic differentiation coefficient (NST) value was significantly greater than the haplotype frequency (GST) (p < 0.05), suggesting that U. macrocarpa had a clear phylogeographical structure. Phylogenetic inference showed that the putative chloroplast haplotypes could be divided into three groups, in which the group Ⅰ was considered to be ancestral. Despite significant genetic differentiation among these groups, gene flow was detected. The common ancestor of all haplotypes was inferred to originate in the middle-late Miocene, followed by the haplotype overwhelming diversification that occurred in the Quaternary. Combined with demography pattern and ecological niche modeling, we speculated that the surrounding areas of Shanxi and Inner Mongolia were potential refugia for U. macrocarpa during the glacial period in Northern China. Our results illuminated the demography pattern of U. macrocarpa and provided clues and references for further population genetics investigations of precious tree species distributed in Northern China.

19.
Adv Mater ; 36(8): e2310651, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38016668

RESUMO

The heterogeneity of perovskite film crystallization along the vertical direction leads to voids and traps at the buried interfaces, hampering both efficiency and stability of perovskite solar cells. Here, bovine serum albumin-functionalized Au nanoclusters (ABSA), combined with heavy gravity, high surface charge density, and strong interactions with the electron transport layer, are designed to reconstruct the buried interfaces for not only high-quality crystallization, but also improved carrier transfer. The ABSA macromolecules with amine function groups and larger surface charge density interact with the perovskite to improve the crystallinity, and gradually migrate towards the buried interface, healing the defective voids, hence suppressing surface recombination velocity from 3075 to 452 cm s-1 . The healed buried interface and the higher surface potential of ABSA-modified TiO2 lead to improved carrier extraction at the interface. The resulting solar cell attains a power conversion efficiency of 25.0% with negligible hysteresis and remarkable stability, maintaining 92.9% of their initial efficiency after 3200 h of exposure to the ambient atmosphere, they also exhibit better continuous irradiation stability compared to control devices. These findings provide a new metal-protein complex to eliminate the deleterious voids and defects at the buried interface for improved photovoltaic performance and stability.

20.
Materials (Basel) ; 16(10)2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37241406

RESUMO

The CuCrSn alloy is promising as a high-strength and high-conductivity Cu alloy due to its relatively low smelting requirement. However, thus far investigations into the CuCrSn alloy are still quite lacking. In this study, the microstructure and properties of Cu-0.20Cr-0.25Sn (wt%) alloy specimens prepared under different rolling and aging combinations were comprehensively characterized, in order to reveal the effects of cold rolling and aging on properties of the CuCrSn. The results show that increasing the aging temperature from 400 °C to 450 °C can noticeably accelerate precipitation, and cold rolling before aging significantly increases its microhardness and promotes precipitation However, the deformation hardening is eliminated during the aging process, making the microhardness decrease monotonically when the aging temperature and the cold rolling ratio before aging are high. Performing cold rolling after aging can maximize precipitation strengthening and deformation strengthening, and the adverse impact on its conductivity is not serious. A tensile strength of 506.5 MPa and a conductivity of 70.33% IACS were obtained by such a treatment, whereas only the elongation decreases a little. Different strength-conductivity combinations of the CuCrSn alloy can be achieved through appropriate design of the aging and post-aging cold rolling conditions.

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