Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81
Filtrar
1.
Cancer Med ; 13(7): e7161, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38613173

RESUMO

BACKGROUND: Ovarian clear cell carcinoma (OCCC) represents a subtype of ovarian epithelial carcinoma (OEC) known for its limited responsiveness to chemotherapy, and the onset of distant metastasis significantly impacts patient prognoses. This study aimed to identify potential risk factors contributing to the occurrence of distant metastasis in OCCC. METHODS: Utilizing the Surveillance, Epidemiology, and End Results (SEER) database, we identified patients diagnosed with OCCC between 2004 and 2015. The most influential factors were selected through the application of Gaussian Naive Bayes (GNB) and Adaboost machine learning algorithms, employing a Venn test for further refinement. Subsequently, six machine learning (ML) techniques, namely XGBoost, LightGBM, Random Forest (RF), Adaptive Boosting (Adaboost), Support Vector Machine (SVM), and Multilayer Perceptron (MLP), were employed to construct predictive models for distant metastasis. Shapley Additive Interpretation (SHAP) analysis facilitated a visual interpretation for individual patient. Model validity was assessed using accuracy, sensitivity, specificity, positive predictive value, negative predictive value, F1 score, and the area under the receiver operating characteristic curve (AUC). RESULTS: In the realm of predicting distant metastasis, the Random Forest (RF) model outperformed the other five machine learning algorithms. The RF model demonstrated accuracy, sensitivity, specificity, positive predictive value, negative predictive value, F1 score, and AUC (95% CI) values of 0.792 (0.762-0.823), 0.904 (0.835-0.973), 0.759 (0.731-0.787), 0.221 (0.186-0.256), 0.974 (0.967-0.982), 0.353 (0.306-0.399), and 0.834 (0.696-0.967), respectively, surpassing the performance of other models. Additionally, the calibration curve's Brier Score (95%) for the RF model reached the minimum value of 0.06256 (0.05753-0.06759). SHAP analysis provided independent explanations, reaffirming the critical clinical factors associated with the risk of metastasis in OCCC patients. CONCLUSIONS: This study successfully established a precise predictive model for OCCC patient metastasis using machine learning techniques, offering valuable support to clinicians in making informed clinical decisions.


Assuntos
Adenocarcinoma de Células Claras , Neoplasias Ovarianas , Feminino , Humanos , Teorema de Bayes , Algoritmos , Carcinoma Epitelial do Ovário , Aprendizado de Máquina
2.
Sci Rep ; 14(1): 7099, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38531885

RESUMO

Rare earth doped up-conversion luminescent nano-materials exhibit abundant emission colors under suitable excitation condition. In this work, NaYF4:Er/Ho@NaYF4 and NaYbF4:Tm@NaYF4 nanoparticles were synthesized by co-precipitation method. The pure red emission can be realized by the designed NaYF4:Er/Ho@NaYF4 nanocrystals and the R/Gs reach 23.3 and 25 under excitations of 980 and 1550 nm lasers, respectively. The R/G declines as the power increasing with the emission color changing from red to yellow, which is due to the quick saturation of the energy levels, radiating red emissions. Meanwhile, the emission intensity of NaYbF4:Tm@NaYF4 nanocrystals increases by 58.3 folds after encasing the inert shell NaYF4 and the CIE color coordinate reaches (0.1646, 0.0602) under 980 nm laser excitation. Furthermore, broad range multicolor from blue to red and yellow up-conversion emissions is achieved by mixing NaYF4:Er/Ho@NaYF4 and NaYbF4:Tm@NaYF4 nanocrystals, which could be applied to colorful displaying, security anti-counterfeiting and information coding.

3.
Artigo em Inglês | MEDLINE | ID: mdl-37917901

RESUMO

Objective: This study aims to investigate the relationship between folic acid (FA) metabolic gene polymorphisms, homocysteine (Hcy), vitamin B12 (Vit B12), and red blood cell folate (RBCF) with adverse pregnancy. The findings of this study can help in the prevention and treatment of adverse pregnancy in the future. Methods: 118 pregnant women admitted to Qingdao Central Hospital between August 2020 and October 2022 were selected for retrospective analysis, including 62 cases of normal delivery (control group, CG) and 56 cases of adverse pregnancy (research group, RG). The single nucleotide polymorphisms of MTHFR C677T, MTHFR A1298C, and MTRR A66G gene loci were tested in both cohorts. Besides, differences in Hcy, Vit B12, and RBCF levels were observed, as well as Hcy, Vit B12, and RBCF alterations in different genotype carriers in the research group. Results: An elevated proportion of MTHFR 677TT-type gene and MTRR 66GG-type gene carriers and a lower proportion of MTRR 66GG-type gene carriers were found in the research group (χ2 = 4.458, 4.238, 4.206, P = .035, .040, .040). As indicated by the Logistic regression analysis, carriers of MTHFR 677TT and MTRR 66GG gene had an increased risk of adverse pregnancy outcomes (95%CI=2.881-5.942, 1.427-3.809, P < .001), while MTRR 66AG carriers had a decreased risk (95%CI=0.124-1.849, P < .001). Finally, Hcy levels of MTHFR 677TT and MTRR 66GG gene carriers increased, while Vit B12 and RBCF decreased; the opposite was true for MTRR 66AG gene carriers (P < .001). Conclusions: FA metabolic gene polymorphisms, Hcy, Vit B12, and RBCF are closely related to adverse pregnancy outcomes, which is of great significance for future clinical evaluation of adverse pregnancy.

4.
Nat Commun ; 14(1): 6813, 2023 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-37884530

RESUMO

Shading in combination with extended photoperiods can cause exaggerated stem elongation (ESE) in soybean, leading to lodging and reduced yields when planted at high-density in high-latitude regions. However, the genetic basis of plant height in adaptation to these regions remains unclear. Here, through a genome-wide association study, we identify a plant height regulating gene on chromosome 13 (PH13) encoding a WD40 protein with three main haplotypes in natural populations. We find that an insertion of a Ty1/Copia-like retrotransposon in the haplotype 3 leads to a truncated PH13H3 with reduced interaction with GmCOP1s, resulting in accumulation of STF1/2, and reduced plant height. In addition, PH13H3 allele has been strongly selected for genetic improvement at high latitudes. Deletion of both PH13 and its paralogue PHP can prevent shade-induced ESE and allow high-density planting. This study provides insights into the mechanism of shade-resistance and offers potential solutions for breeding high-yielding soybean cultivar for high-latitude regions.


Assuntos
Estudo de Associação Genômica Ampla , /genética , Melhoramento Vegetal , Fenótipo , Retroelementos
5.
Medicine (Baltimore) ; 102(43): e35530, 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37904386

RESUMO

The pathogenesis of depression is unclear, and it responds poorly to treatment. It is thus urgent to identify the pathogenesis of depression and possible therapeutic targets. There may be interactions between insulin resistance (IR) and depression. The purpose of this study was to explore the relationship between depression, triglyceride glucose (TyG) index. The study participants were 198 middle-aged and elderly patients who were admitted to the Hebei General Hospital between January 1, 2021, and August 31, 2022, together with 189 healthy adults as controls. Depression was diagnosed according to ICD-10 diagnostic criteria for depression. IR was assessed by the TyG index. Compared with the control group, patients suffering from depression had higher TyG index (P = .00); There were significant differences in the sex ratio (P = .00), family history (P = .00), body mass index (P = .008), total cholesterol (P = .00), fasting blood glucose (P = .004), high-density lipoprotein (P = .00), and low-density lipoprotein (P = .001) levels between the 2 groups. After excluding other confounding factors, the TyG index was found to be independently associated with depression, with an OR of 2.75. These data support an association of depression with the TyG index. IR thus appears to be a risk factor for depression.


Assuntos
Glucose , Resistência à Insulina , Idoso , Pessoa de Meia-Idade , Humanos , Adulto , Triglicerídeos , Estudos Transversais , Glicemia , Depressão/epidemiologia , Biomarcadores
6.
ArXiv ; 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-37292471

RESUMO

As machine learning (ML) algorithms are increasingly used in high-stakes applications, concerns have arisen that they may be biased against certain social groups. Although many approaches have been proposed to make ML models fair, they typically rely on the assumption that data distributions in training and deployment are identical. Unfortunately, this is commonly violated in practice and a model that is fair during training may lead to an unexpected outcome during its deployment. Although the problem of designing robust ML models under dataset shifts has been widely studied, most existing works focus only on the transfer of accuracy. In this paper, we study the transfer of both fairness and accuracy under domain generalization where the data at test time may be sampled from never-before-seen domains. We first develop theoretical bounds on the unfairness and expected loss at deployment, and then derive sufficient conditions under which fairness and accuracy can be perfectly transferred via invariant representation learning. Guided by this, we design a learning algorithm such that fair ML models learned with training data still have high fairness and accuracy when deployment environments change. Experiments on real-world data validate the proposed algorithm. Model implementation is available at https://github.com/pth1993/FATDM.

7.
Medicine (Baltimore) ; 102(24): e34058, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37327285

RESUMO

The triglyceride-glucose (TyG) index has been proposed as a new marker for insulin resistance, which is associated with a risk of major depressive disorder (MDD). This study aims to explore whether the TyG index is correlated with MDD. In total, 321 patients with MDD and 325 non-MDD patients were included in the study. The presence of MDD was identified by trained clinical psychiatrists using the International Classification of Diseases 10th Revision. The TyG index was calculated as follows: Ln (fasting triglyceride [mg/dL] × fasting glucose [mg/dL]/2). The results revealed that the MDD group presented higher TyG index values than the non-MDD group (8.77 [8.34-9.17] vs 8.62 [8.18-9.01], P < .001). We also found significantly higher morbidity of MDD in the highest TyG index group than in the lower TyG index group (59.9% vs 41.4%, P < .001). Binary logistic regression revealed that TyG was an independent risk factor for MDD (odds ratio [OR] 1.750, 95% confidence interval: 1.284-2.384, P < .001). We further assessed the effect of TyG on depression in sex subgroups. The OR was 3.872 (OR 2.014, 95% confidence interval: 1.282-3.164, P = .002) for the subgroup of men. It is suggested that the TyG index could be closely associated with morbidity in MDD patients; thus, it may be a valuable marker for identifying MDD.


Assuntos
Transtorno Depressivo Maior , Resistência à Insulina , Masculino , Humanos , Glucose , Estudos Transversais , Glicemia , Triglicerídeos , Biomarcadores , Fatores de Risco
8.
Knowl Inf Syst ; 65(4): 1487-1521, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36998311

RESUMO

In healthcare domain, complication risk profiling which can be seen as multiple clinical risk prediction tasks is challenging due to the complex interaction between heterogeneous clinical entities. With the availability of real-world data, many deep learning methods are proposed for complication risk profiling. However, the existing methods face three open challenges. First, they leverage clinical data from a single view and then lead to suboptimal models. Second, most existing methods lack an effective mechanism to interpret predictions. Third, models learned from clinical data may have inherent pre-existing biases and exhibit discrimination against certain social groups. We then propose a multi-view multi-task network (MuViTaNet) to tackle these issues. MuViTaNet complements patient representation by using a multi-view encoder to exploit more information. Moreover, it uses a multi-task learning to generate more generalized representations using both labeled and unlabeled datasets. Last, a fairness variant (F-MuViTaNet) is proposed to mitigate the unfairness issues and promote healthcare equity. The experiments show that MuViTaNet outperforms existing methods for cardiac complication profiling. Its architecture also provides an effective mechanism for interpreting the predictions, which helps clinicians discover the underlying mechanism triggering the complication onsets. F-MuViTaNet can also effectively mitigate the unfairness with only negligible impact on accuracy.

9.
J Inorg Biochem ; 239: 112048, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36496289

RESUMO

Six new Pd(II), Pt(II) and Ag(I) complexes, (1);{Pd (L1)]2C6H4}2Cl4} (2); Pt(L2)(DMSO)Cl; 3; {PtL5]2C6H4}2·PhCOO-⋅11NO3-; 4; {[Pt(L4)]2C6H4}; the binuclear cyclometalated complex the polymer chain (5); {[PtL5]C6H4}·NO3-}; and the polymeric silver species (6); Zn(L6)2·AgNO3·CHCl3 were synthesized and thoroughly characterized using X-ray diffraction and spectroscopic techniques (L1=(S,S)-1,4-i-PrOx]2C6H4}2Cl4, L2=Di(2,2-bis(4R-isopropyl-4,5-dihydro-oxazol-2-yl)acetonitrile) zinc (II) (BR1);L3= 1,4-bis(4R-benzyl-4,5-dihydro-oxazol-2-yl)benzene (AR2); L4= 1,4-bis(4R-benzyl-4,5-dihydro-oxazol-2-yl)benzene,L5=1,4-bis(4R-benzyl-4,5-dihydro-oxazol-2-yl)-benzene,L6=Di(2,2-bis(4S-isopropyl-4,5-dihydrooxazol-2-yl)acetonitrile) zinc (II). Complexes 1-6 showed cytotoxic effects against human tumour cell lines, including a multidrug-resistant subline. Oxazoline and Pd complex 1 induced apoptosis in A549 cells. DFT calculations were also performed to exhibit the excellent bioactivity of complex 1 against A549, MDA-MB-231, and KB cells. Complex 1, with the best docking score and a stable interaction network within the binding site of the G-quadruplex, could stably interact with the G-quadruplex. Additionally, complex 1 was further used in the animal experiment of human lung adenocarcinoma cells in nude mice. By comparing with the model control group, the tumour volume, relative tumour volume and relative tumour proliferation rate T/C decreased significantly in the cisplatin group and compound 1 (complex 1) group.


Assuntos
Antineoplásicos , Platina , Animais , Camundongos , Humanos , Platina/farmacologia , Platina/química , Simulação de Acoplamento Molecular , Paládio/farmacologia , Paládio/química , Prata/farmacologia , Teoria da Densidade Funcional , Benzeno , Camundongos Nus , Linhagem Celular Tumoral , Antineoplásicos/química , Zinco
10.
Opt Express ; 30(26): 47485-47496, 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36558676

RESUMO

The process and condition of saturable absorption (SA) and reverse saturable absorption (RSA) of ultrafast nonlinear optics in metal nanoparticles are essential for applications including light generation, amplification, modulation, and switching. Here, we first discover and explore the multiple transformations (SA-RSA-SA) of ultrafast nonlinear absorption behavior of metal nanoparticles in femtosecond pulses. Correspondingly, the energy level model and fitting formula of multiple transformations are established to illustrate the process of optical response. The femtosecond transient absorption spectra provide information about their ultrafast dynamics process and vibrational mode, which further reveals the multiple transformation mechanisms of nonlinear absorption in gold nanobipyramids (Au-NBPs). Furthermore, Au-NBPs exhibit a significantly higher SA modulation depth up to 42% in the femtosecond, which is much higher than the reported values of other nanomaterials. Our results indicate that Au-NBPs can be used as broadband ultrafast Q-switching and mode-locking, and the conversion offers new opportunities for metal nanostructures in applications of optical switching.

11.
Front Oncol ; 12: 888570, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36518303

RESUMO

Background: An increasing number of studies have revealed the influencing factors of ferroptosis. The influence of immune cell infiltration, inflammation development and lipid metabolism in the tumor microenvironment (TME) on the ferroptosis of tumor cells requires further research and discussion. Methods: We explored the relationship between ferroptosis-related genes and acute myeloid leukemia (AML) from the perspective of large sample analysis and multiomics, used multiple groups to identify and verify ferroptosis-related molecular patterns, and analyzed the sensitivity to ferroptosis and the state of immune escape between different molecular pattern groups. The single-sample gene set enrichment analysis (ssGSEA) algorithm was used to quantify the phenotypes of ferroptosis-related molecular patterns in individual patients. HL-60 and THP-1 cells were treated with ferroptosis inducer RSL3 to verify the therapeutic value of targeted inhibition of GPX4. Results: Three ferroptosis-related molecular patterns and progressively worsening phenotypes including immune activation, immune exclusion and immunosuppression were found with the two different sequencing approaches. The FSscore we constructed can quantify the development of ferroptosis-related phenotypes in individual patients. The higher the FSscore is, the worse the patient's prognosis. The FSscore is also highly positively correlated with pathological conditions such as inflammation development, immune escape, lipid metabolism, immunotherapy resistance, and chemotherapy resistance and is negatively correlated with tumor mutation burden. Moreover, RSL3 can induce ferroptosis of AML cells by reducing the protein level of GPX4. Conclusions: This study revealed the characteristics of immunity, inflammation, and lipid metabolism in the TME of different AML patients and differences in the sensitivity of tumor cells to ferroptosis. The FSscore can be used as a biomarker to provide a reference for the clinical evaluation of the pathological characteristics of AML patients and the design of personalized treatment plans. And GPX4 is a potential target for AML treatment.

12.
Spectrochim Acta A Mol Biomol Spectrosc ; 281: 121608, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-35843059

RESUMO

Na3Y(VO4)2:Nd3+,Yb3+,Ho3+,Tm3+ phosphors present significantly improved sensitivity of optical temperature sensing based on thermal-enhanced upconversion luminescence and non-thermally coupled energy levels. Under 808 nm excitation, white upconversion luminescence is successfully achieved in Nd3+-sensitized system. In addition, the emissions intensities originated from 4G5/2→4I9/2 transition of Nd3+ and 3F2,3→3H6 transition of Tm3+ gradually increase with elevating temperature owning to the thermal population effects, as opposed to the blue (1G4→3H6 transition of Tm3+), green (5S2,5F4→5I8 transition of Ho3+) and red (5F5→5I8 transition of Ho3+) emissions intensities show continuous decreasing trend. The temperature sensing behaviors are investigated by employing multiple non-thermally coupled energy levels. Based on non-thermally coupled energy levels of 4G5/2 (Nd3+)/1G4 (Tm3+), the absolute and relative sensitivities are obtained to be 0.433 K-1 and 2.81 % K-1. These results demonstrate that the Na3Y(VO4)2:Nd3+,Yb3+,Ho3+,Tm3+ phosphors with superior optical thermometry performance and white luminescence within a relatively wide temperature range can achieve optical applications in many fields.

13.
J Colloid Interface Sci ; 624: 287-295, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35660898

RESUMO

The emission linewidth of quantum dots (QDs) is one of the important optical properties, which is essential for the applications of QD lasers, high-quality displays, and biological imaging. However, we know less about controlling emission linewidth and its underlying mechanisms. Here we introduce a wurtzite ZnSe shell onto a wurtzite CdSe core to produce asymmetric strain due to their large, anisotropic lattice mismatch. Such asymmetric pressure induces significant splitting (ΔAB) between heavy-hole (hh) and light-hole (lh) in valence band (VB). We show that the emission intensity from the lh state (Elh) is significantly suppressed with the increasing ΔAB caused by the strong asymmetric strain. We demonstrate that the exciton-phonon coupling (EPC) is greatly inhibited under the anisotropic lattice strain. The alloying process between the core and shell occurs under the strong lattice strain and raises the longitudinal-optical (LO) phonon energy (ELO). Higher LO phonon energy declines LO phonon occupation numbers (NLO) and synergistically reduces the EPC. The asymmetrically strained alloy QDs ensemble exhibits highly bright emission with ultra-narrow linewidths of 13.8 nm (∼520 nm) and 15.8 nm (∼620 nm). This concept of band structure regulation via asymmetric strain can provide a new platform for high-quality QDs beyond the currently achieved.


Assuntos
Pontos Quânticos , Ligas , Pontos Quânticos/química
14.
Molecules ; 27(11)2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35684501

RESUMO

A novel two-branched twistacene (PyDN) has been designed and synthesized for application on ultrafast optical limiting. This twistacene exhibits excellent two photon absorption and two photon absorption-induced excited singlet state absorption, which was systematically investigated with a femtosecond Z-scan experiment, transient absorption spectrum, and two-photon excited fluorescence experiments. The admirable two photon absorption is attributed to the high degree of π electron delocalization in twistacene which is caused by introduction of two strong donors. The excited singlet state absorption cooperates with two-photon absorption to provide an excellent ultrafast optical limiting behavior with high linear transmittance, where the thresholds are 2.3-5.3 mJ/cm2 in the spectral region of 532-800 nm of femtosecond laser and 133 mJ/cm2 for picosecond pulse at 532 nm. These thresholds are lower than that of most of the optical limiters reported previously, which indicates PyDN is a promising candidate for ultrafast optical limiting.

15.
Molecules ; 27(9)2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35566197

RESUMO

The linear and nonlinear optical properties of two BODIPY derivatives, 1,7-Diphenyl-3,5-bis(9,9-dimethyl-9H-fluoren-2-yl)-boron-diuoride-azadipyrromethene (ZL-61) and 1,7-Diphenyl-3,5-bis(4-(1,2,2-triphenylvinyl)phenyl)-boron-diuoride-azadipyrromethene (ZL-22), were comprehensively investigated based on experimental and theoretical studies. It was found that both compounds show a strong two-photon absorption response in the near-infrared regime, and the two-photon-absorption cross-section values of ZL-61 and ZL-22 were determined to be 8321 GM and 1864 GM at 800 nm, respectively. The improvement of the two-photon absorption cross section in ZL-61 was attributed to the enhancement of the donor group, which was confirmed by transient absorption measurements and DFT calculation. Our results indicate that these BODIPY derivatives are a promising candidate for optical limiting and two-photon imaging applications.


Assuntos
Boro , Corantes Fluorescentes , Compostos de Boro , Porfobilinogênio/análogos & derivados
16.
Opt Express ; 30(7): 10354-10366, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35473005

RESUMO

We first present the all-optical realization of a scalable super-resolved magnetic vortex core (MVC) by tightly focusing two modulated counter-propagating radially polarized doughnut Gaussian beams based on the vectoial diffraction theory and the inverse Faraday effect. It is shown that by imposing spiral phase plates (SPPs) on the incident vectorial beams, single three-dimensional (3D) super-resolved (λ3/22) MVC can be achieved in the 4π focusing setup, which is radically different from that produced with a single lens focusing. Furthermore, the light-induced MVC texture turns to be richer and more complex when the radially polarized beams are tailored by the SPPs and judiciously designed multi-ring filters all together. In this case, we are able to garner not only transverse super-resolved (0.447λ) MVC needle with an uniformly extended area (40λ) in the single lens focusing system, but also the multiple uniform 3D super-resolved (λ3/24) chain-like MVC cells in the 4π focusing system, thus giving rise to the tunable and scalable super-resolved MVC extension. The related physical mechanisms to trigger such peculiar magnetization polarization topologies are unraveled as well. These resultant achievements would pave the way for the integrated transfer and storage of optomagnetic information, atomic trapping, and beyond.

17.
Opt Express ; 30(7): 11549-11562, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35473097

RESUMO

Hyperbolic metamaterials (HMMs) exhibit rich optical nonlinear responses for the epsilon-near-zero (ENZ) and anisotropy. In this study, we extract the time-dependent change in the effective permittivity of an Ag nanorod array under femtosecond pulses pumping around its ENZ wavelength. The transmittance and transient absorption spectra measured by s- and p-polarizations are used in the extraction process. We experimentally confirm the existence of an ultrafast recovery process with a relaxation time of 0.24 ps in the transient absorption spectra. The calculation based on the extracted nonlinear effective permittivity indicates that the ultrafast signal originates from the superposition of two slower recovery processes, with relaxation times of 0.74 ps and 1.19 ps, respectively. The results indicate that when the responses of two nonlinear processes have different signs and recovery speeds, their superposition may cause faster signal recovery in the combined process than in the two individual processes.

18.
Artigo em Inglês | MEDLINE | ID: mdl-35409974

RESUMO

Global climate change results in an increased risk of high urban temperatures, making it crucial to conduct a comprehensive assessment of the high-temperature risk of urban areas. Based on the data of 194 meteorological stations in China from 1986 to 2015 and statistical yearbooks and statistical bulletins from 2015, we used GIS technology and mathematical statistics to evaluate high-temperature spatial and temporal characteristics, high-temperature risk, and high-temperature vulnerability of 31 cities across China. Over the past 30 years, most Chinese cities experienced 5-8 significant oscillation cycles of high-temperature days. A 15-year interval analysis of high-temperature characteristics found that 87% of the cities had an average of 5.44 more high-temperature days in the 15-year period from 2001 to 2015 compared to the period from 1986 to 2000. We developed five high-temperature risk levels and six vulnerability levels. Against the background of a warming climate, we discuss risk mitigation strategies and the importance of early warning systems.


Assuntos
Temperatura Alta , China/epidemiologia , Cidades , Medição de Risco , Temperatura
19.
J Phys Chem B ; 126(17): 3327-3337, 2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35452239

RESUMO

Optical limiting (OL) is an important application of nonlinear optics. Summarizing the structure-property relationship of organic materials is an effective means to develop superior optical limiters. In this work, two triphenylamine-based chalcone derivatives T1 and T2 with different peripheral substituent groups were synthesized to study their transient kinetics and nonlinear optical (NLO) absorption performance. The transient absorption spectrum (TAS) of compounds T1 and T2 in solvents of varying polarities visualizes the intramolecular charge transfer (ICT) processes between the local excited state (LES) and the charge transfer state (CTS). Nanosecond Z-scan experiment and hole-electron analysis indicate that all compounds have excellent reverse saturated absorption (RSA) performance at 532 nm and T1 exhibits stronger RSA than T2 due to the stronger ICT performance of T1 caused by the halogen effect. Degenerate pump-probe experiment shows that the ESA of T2 at 532 nm is significantly enhanced by expanding the molecular π-conjugation. Under the premise of consistent linear transmittance (78%), compound T2 shows better OL performance than compound T1 at 532 nm in the nanosecond time domain. The OL thresholds of T1 and T2 are 3.72 and 0.72 J cm-2, respectively, which are better than those of the most reported OL materials. Our research shows that simple and common chalcone derivatives exhibit amazing NLO performance through a reasonable design.

20.
J Dairy Sci ; 105(6): 4749-4759, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35450717

RESUMO

As one of the main ingredients in some milk powders, whey powder is sometimes added to pure goat milk products, which can cause health risks, economic fraud, and unfair competition of food industries. This study is the first to explore qualitative and quantitative methods to identify adulteration of bovine whey powder in goat dairy products based on DNA. We extracted DNA from whey powder using a modified DNA extraction method; this exhibited good quality and integrity, with purity of 1.53 to 1.75 and concentration of 122 to 179 ng/µL. Conventional PCR and real-time PCR were compared for qualitative detection of bovine whey powder; real-time PCR demonstrated sensitivity of 0.01 ng/µL, which was higher than the 0.05 ng/µL detected by the conventional PCR method. Furthermore, real-time PCR was conducted for DNA quantitative detection, with good linearity (R2 = 0.9858) obtained for bovine whey powder contents from 0.1% to 30%. Relative error decreased with increase of the mixing proportion of whey powder; the coefficient of variation above 0.1% of the mixing ratio was close to or less than 5%; and the relative standard deviation of repeatability results was less than 5%. Considering the economic costs of testing, conventional PCR could be performed first, and samples with obvious intentional adulteration detected can be further accurately quantified by real-time PCR. Overall, this research provides a realistic and effective method for qualitative and quantitative identification of bovine whey powder in goat dairy products, thus laying a good foundation for verification of goat dairy product label claims and industrial control.


Assuntos
Cabras , Soro do Leite , Animais , Bovinos , DNA/análise , Laticínios/análise , Leite/química , Pós , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Soro do Leite/química , Proteínas do Soro do Leite
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...