Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
Mais filtros










Base de dados
Tipo de estudo
Intervalo de ano de publicação
1.
Public Health Nutr ; : 1-10, 2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31928552

RESUMO

OBJECTIVE: Globally, China is among the 'saltiest' nations. In order to support current nationwide salt reduction initiatives, we investigated Chinese consumers' knowledge, beliefs and behaviours related to salt intake and salt reduction. DESIGN: A cross-sectional face-to-face survey was carried out, focusing on salt knowledge, beliefs and behaviours related to salt intake and salt reduction, perceptions of salt reduction responsibility and support for different national strategies. SETTING: The survey was carried out in China mainland. PARTICIPANTS: Consumers (n 2444) from six of seven major geographical regions in China participated in the survey. After data cleaning, a sample of 2430 was included in the final analysis. RESULTS: A majority of Chinese consumers believed that salt added during home cooking was the biggest contributor to their salt intake. Knowledge gaps existed in the awareness of salt hidden in certain foods and flavouring products. Chinese consumers in general were interested in lowering their salt intake. They were aware of salt reduction tools, but the adoption level was low. Consumers expressed strong support for promotion of salt-restriction spoons and public education, but not fiscal policies (e.g. salt-related tax or subsidies). In terms of individual differences, education status demonstrated a substantial impact on salt reduction knowledge and behaviour. CONCLUSIONS: There is still big room to 'shake' Chinese consumers' salt habit. The present study provides important evidence and consumer insights to support China's efforts to meet its salt reduction targets.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31846190

RESUMO

Formamidinium (FA) lead iodide perovskite materials feature promising photovoltaic performances and superior thermal stabilities. However, conversion of the perovskite α-FAPbI3 phase to the thermodynamically stable yet photovoltaically inactive δ-FAPbI3 phase compromises the photovoltaic performance. A strategy is presented to address this challenge by using low-dimensional hybrid perovskite materials comprising guaninium (G) organic spacer layers that act as stabilizers of the three-dimensional α-FAPbI3 phase. The underlying mode of interaction at the atomic level is unraveled by means of solid-state nuclear magnetic resonance spectroscopy, X-ray crystallography, transmission electron microscopy, molecular dynamics simulations, and DFT calculations. Low-dimensional-phase-containing hybrid FAPbI3 perovskite solar cells are obtained with improved performance and enhanced long-term stability.

3.
Bioorg Med Chem ; 27(23): 115153, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31648877

RESUMO

In this study, a series of shikonin derivatives combined with benzoylacrylic had been designed and synthesized, which showed an inhibitory effect on both tubulin and the epidermal growth factor receptor (EGFR). In vitro EGFR and cell growth inhibition assay demonstrated that compound PMMB-317 exhibited the most potent anti-EGFR (IC50 = 22.7 nM) and anti-proliferation activity (IC50 = 4.37 µM) against A549 cell line, which was comparable to that of Afatinib (EGFR, IC50 = 15.4 nM; A549, IC50 = 6.32 µM). Our results on mechanism research suggested that, PMMB-317 could induce the apoptosis of A549 cells in a dose- and time-dependent manner, along with decrease in mitochondrial membrane potential (MMP), production of ROS and alterations in apoptosis-related protein levels. Also, PMMB-317 could arrest cell cycle at G2/M phase to induce cell apoptosis, and inhibit the EGFR activity through blocking the signal transduction downstream of the mitogen-activated protein MAPK pathway and the anti-apoptotic kinase AKT pathway; typically, such results were comparable to those of afatinib. In addition, PMMB-317 could suppress A549 cell migration through the Wnt/ß-catenin signaling pathway in a dose-dependent manner. Additionally, molecular docking simulation revealed that, PMMB-317 could simultaneously combine with EGFR protein (5HG8) and tubulin (1SA0) through various forces. Moreover, 3D-QSAR study was also carried out, which could optimize our compound through the structure-activity relationship analysis. Furthermore, the in vitro and in vivo results had collectively confirmed that PMMB-317 might serve as a promising lead compound to further develop the potential therapeutic anticancer agents.

4.
J Phys Chem Lett ; 10(21): 6865-6872, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31599595

RESUMO

Solution-processable organic-inorganic perovskite solar cells have attracted much attention in the past few years. Energy level alignment is of great importance for improving the performance of perovskite solar cells because it strongly influences charge separation and recombination. In this report, we introduce three amide additives, namely, formamide, acetamide, and urea, into the MAPbI3 perovskite by mixing them directly in perovskite precursor solutions. The Fermi level of MAPbI3 shifts from -4.36 eV to -4.63, -4.65, and -4.61 eV, respectively, upon addition of these additives. The charge transfer between perovskite and mp-TiO2 is found to be promoted as determined via TRPL spectra, and recombination in the perovskite is suppressed. As a result, the built-in electric field (Vbi) of the printable, hole-conductor-free mesoscopic perovskite solar cells based on these perovskites with amide additives is enhanced and a peak power conversion efficiency of 15.57% is obtained.

5.
Biomaterials ; 224: 119478, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31542517

RESUMO

The Liver is the most common organ for metastasis for various cancers, including uveal melanoma, the most common primary intraocular tumor. Uveal melanoma metastasizes to the liver in ~90% of patients, and results in death in almost all cases due to late detection and lack of effective treatment. There is a pressing unmet medical need to develop MRI contrast agents and imaging methodologies with desired sensitivity and specificity to overcome the high heterogeneous background and in vivo properties as well as reduced toxicity. Herein, we report the development of a collagen targeting protein contrast agent (ProCA32.collagen1), since collagen is a diagnostic biomarker and therapeutic target for many types of primary and metastatic cancers and the tumor microenvironment. In addition to a strong affinity to collagen I, ProCA32.collagen1 possesses high relaxivities (r1 and r2 are 68.0 ±â€¯0.25 and 100.0 ±â€¯0.32 mM-1 s-1 at 1.4 T, respectively, and 42.6 ±â€¯1.0 and 217 ±â€¯2.4 mM-1s-1 at 7.0 T per particle). ProCA32.collagen1 also has strong serum stability against degradation, resistance to transmetallation, and 102 and 1013-fold higher metal selectivity for Gd3+ over Ca2+ and Zn2+, respectively, compared to clinical contrast agents. ProCA32.collagen1 does not exhibit any cell toxicity for various cell lines. Sensitive detection of liver lesions in animal models can be achieved using multiple imaging methodologies, taking advantage of the dual relaxation property of ProCA32.collagen1. ProCA32.collagen1 enables sensitive and early stage detection of hepatic micrometastasis as small as 0.144 mm2 and two different tumor growth patterns. Further development of ProCA32.collagen1 has the potential to greatly facilitate non-invasive, early detection and staging of primary and metastatic liver cancers, and devising effective treatments.

6.
Int J Mol Sci ; 20(18)2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31500111

RESUMO

Purple turnip Brassica rapa ssp. rapa is highly appreciated by consumers but the metabolites and molecular mechanisms underlying the root skin pigmentation remain open to study. Herein, we analyzed the anthocyanin composition in purple turnip (PT) and green turnip (GT) at five developmental stages. A total of 21 anthocyanins were detected and classified into the six major anthocynanin aglycones. Distinctly, PT contains 20 times higher levels of anthocyanins than GT, which explain the difference in the root skin pigmentation. We further sequenced the transcriptomes and analyzed the differentially expressed genes between the two turnips. We found that PT essentially diverts dihydroflavonols to the biosynthesis of anthocyanins over flavonols biosynthesis by strongly down-regulating one flavonol synthase gene, while strikingly up-regulating dihydroflavonol 4-reductase (DFR), anthocyanidin synthase and UDP-glucose: flavonoid-3-O-glucosyltransferase genes as compared to GT. Moreover, a nonsense mutation identified in the coding sequence of the DFR gene may lead to a nonfunctional protein, adding another hurdle to the accumulation of anthocyanin in GT. We also uncovered several key members of MYB, bHLH and WRKY families as the putative main drivers of transcriptional changes between the two turnips. Overall, this study provides new tools for modifying anthocyanin content and improving turnip nutritional quality.

7.
ACS Appl Mater Interfaces ; 11(37): 33879-33885, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31438676

RESUMO

Hexagonal selenium with a direct band gap has been developed for optoelectronic applications for more than one century. The major advances in Se solar cells have been made using vacuum or solution-based processing methods. In this work, we demonstrate a new two-stage melt processing (TSMP) method for incorporating Se in printable triple mesoscopic solar cells in the ambient conditions. It is observed that polymerization and depolymerization between several types of selenium chains are simultaneously triggered during the melt processing, from which phase-pure hexagonal selenium is formed in the mesopores of solar cells with high crystallinity. The TSMP method has positive effects on the conduction-band energy level, band gap, and crystal phase of as-deposited Se, as revealed UV electron spectroscopy, UV-vis absorption spectroscopy, and in situ X-ray diffraction. The TSMP-based printable mesoscopic selenium solar cells show a power conversion efficiency of 2%, which is eight times that for devices based on the single-stage melting processing. These findings open up a new research direction of melting processing toward more efficient photovoltaic devices.

8.
ACS Appl Mater Interfaces ; 11(31): 27648-27657, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31305062

RESUMO

With respect to cyanoacryclic acid as the traditional acceptor and anchoring group in dye-sensitized solar cells, the introduction of stronger electron-deficient groups has greatly expanded the scope of molecular design and increased their efficiencies for organic dyes. In this contribution, benzothiadiazole (BTD) was selected as a representative acceptor to illustrate the influence of its position on the photophysical properties and corresponding photovoltaic performances. Through the insertion of BTD in different positions of the framework with the same composition units and orders, four sensitizers were designed and synthesized. The structure-property relationship demonstrated the preference of the suitable position of an electron acceptor for optimization of the spectra response and interfacial charge transfer. In our system, dye LI-96 with BTD in the middle of the conjugated bridge showed the broadest spectrum and achieved the best photovoltaic performance (8.25%), which may pave a new way to design or optimize the efficient sensitizers by rational design of the acceptor position.

9.
Chem Commun (Camb) ; 55(19): 2765-2768, 2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-30768077

RESUMO

A low-temperature carbon electrode with good perovskite compatibility is employed in hole-transport-material free perovskite solar cells, and a champion power conversion efficiency (PCE) of 11.7% is obtained. The PCE is enhanced to 14.55% by an interface modification of PEDOT:PSS. The application of this carbon on ITO/PEN substrates is also demonstrated.

10.
Chemistry ; 24(68): 18032-18042, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30307090

RESUMO

A tetraaryl-1,4-dihydropyrrolo-[3,2-b]pyrroles (TAPP) moiety with the combination of two pyrrole rings and four phenyl moieties demonstrated strong electron-donating ability and nonplanar configuration simultaneously. Once incorporated into the organic dyes as a novel electron donor, it was beneficial for the enhancement of light-harvesting ability and suppression of electron recombination in the photovoltaic and photocatalysis systems. With the linkage of tunable conjugated bridges and electron acceptor, the corresponding organic dyes exhibited improved photovoltaic performance in dye-sensitized solar cells and facilitated photocatalytic hydrogen generation with a highest turnover number (TON) of 4337. Through the detailed investigation of relationship between molecular structures and photovoltaic/photocatalysis property, the connection and difference in molecular design for these two systems are well explained, with the aim to promote the application of dye-sensitized technology in various fields.

11.
Chem Biodivers ; 15(11): e1800289, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30194898

RESUMO

A number of podophyllotoxin derivatives (3A-3J) had been designed and synthesized, and their biological activities were evaluated in this study. Moreover, the antiproliferation activities of these compounds against four human cancer cell lines (HepG2, HeLa, A549, and MCF-7) were also tested. The results indicated that the most promising compound 3D displayed potent inhibitory activity over the four human cancer cell lines and was further demonstrated to have potent tubulin polymerization inhibitory effects without damaging the non-cancer cells. Additionally, 3D was verified to effectively interfere with tubulin and could prevent the mitosis of cancer cells, leading to cell cycle arrest and eventually inducing apoptosis in a dose- and time-dependent manner. Moreover, the Western blotting and siRNA results showed that Bcl-2 was downregulated in HepG2 cells treated with 3D. Finally, the molecular docking simulation results revealed that 3D could fit well in the colchicine-binding pocket. Taken together, this study has provided certain novel antitubulin agents for possible cancer chemotherapy.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Podofilotoxina/farmacologia , Tubulina (Proteína)/metabolismo , Antineoplásicos Fitogênicos/síntese química , Antineoplásicos Fitogênicos/química , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Conformação Molecular , Simulação de Acoplamento Molecular , Podofilotoxina/síntese química , Podofilotoxina/química , Relação Estrutura-Atividade , Células Tumorais Cultivadas
12.
Science ; 361(6408)2018 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-30237326

RESUMO

Perovskite solar cells (PSCs) have witnessed rapidly rising power conversion efficiencies, together with advances in stability and upscaling. Despite these advances, their limited stability and need to prove upscaling remain crucial hurdles on the path to commercialization. We summarize recent advances toward commercially viable PSCs and discuss challenges that remain. We expound the development of standardized protocols to distinguish intrinsic and extrinsic degradation factors in perovskites. We review accelerated aging tests in both cells and modules and discuss the prediction of lifetimes on the basis of degradation kinetics. Mature photovoltaic solutions, which have demonstrated excellent long-term stability in field applications, offer the perovskite community valuable insights into clearing the hurdles to commercialization.

13.
J Phys Chem Lett ; 9(10): 2707-2713, 2018 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-29738259

RESUMO

Perovskite solar cells (PSCs) have attracted intensive attention of the researchers and industry due to their high efficiency, low material cost, and simple solution-based fabrication process. Along with the development of device configurations, materials, and fabrication techniques, the efficiency has rapidly increased from the initial 3.8 to recent 22.7%. However, fundamental studies on PSCs are usually yielded through lab-scale procedures and carried out on small-area (≤1 cm2) devices. Recently, various deposition methods, such as screen printing, slot-die coating, soft-cover coating, spraying coating, etc., have been developed to enlarge the device area from the millimeters to hundreds of centimeters scale. Herein, we discuss the advances of up-scaling of PSCs and outline the fabrication methods from lab-scale to industrial-scale. Screen printing and slot-die coating have been regarded as the most promising methods toward the mass production of PSCs, and more emerging techniques are also anticipated in this enterprise.

14.
Dalton Trans ; 47(20): 7050-7058, 2018 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-29741166

RESUMO

We report on the synthesis, crystal structures, optoelectronic properties and solar cell device studies of three novel organic-inorganic iodobismuthates - [C3H4NS]3[Bi2I9] ([TH]3[Bi2I9]), [C3H4N2]3[Bi2I9] ([IM]3[Bi2I9]) and [C3H5N2S][BiI4] ([AT][BiI4]) as lead-free light harvesters. [TH]3[Bi2I9] and [IM]3[Bi2I9] show zero-dimensional structures, whereas a one-dimensional edge-sharing chain structure of BiI6-octahedra was observed in [AT][BiI4], with interchain short II contacts also giving rise to the possibility of three-dimensional charge transport ability. Accordingly, greater energy dispersion in the band structure of [AT][BiI4] can be observed, and less contribution from the organic moities at the conduction band minimum in [AT][BiI4] than [TH]3[Bi2I9] have been confirmed by density functional theory calculations. Moreover, bandgap values are redshifted from 2.08 eV for [TH]3[Bi2I9] and 2.00 eV for [IM]3[Bi2I9] to 1.78 eV for [AT][BiI4], determined by UV-Vis reflectance spectroscopy. Power conversion efficiency of 0.47% has been achieved by using ([AT][BiI4]) as the light absorber in a hole-conductor-free, fully printable solar cell, with relatively good reproducibility. We also note the observation of a capacitance effect for the first time in a photovoltaic device with bismuth-based solar absorber, which may be related to the mesoporous carbon counter-electrode.

15.
ACS Appl Mater Interfaces ; 10(13): 10835-10841, 2018 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-29558106

RESUMO

Printable mesoscopic perovskite solar cells (PMPSCs) have exhibited great attractive prospects in the energy conversion field due to their high stability and potential scalability. However, the thick perovskite film in the mesoporous layers challenges the charge transportation and increase grain boundary defects, limiting the performance of the PMPSCs. It is critical not only to improve the electric property of the perovskite film but also to passivate the charge traps to improve the device performance. Herein we synthesized a bis-adduct 2,5-(dimethyl ester) C60 fulleropyrrolidine (bis-DMEC60) via a rational molecular design and incorporated it into the PMPSCs. The enhanced chemical interactions between perovskite and bis-DMEC60 improve the conductivity of the perovskite film as well as elevate the passivation effect of bis-DMEC60 at the grain boundaries. As a result, the fill factor (FF) and power conversion efficiency (PCE) of the PMPSCs containing bis-DMEC60 reached 0.71 and 15.21%, respectively, significantly superior to the analogous monoadduct derivative (DMEC60)-containing and control devices. This work suggests that fullerene derivatives with multifunctional groups are promising for achieving high-performance PMPSCs.

16.
Adv Mater ; 30(11)2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29377428

RESUMO

A bifunctional conjugated organic molecule 4-(aminomethyl) benzoic acid hydroiodide (AB) is designed and employed as an organic cation in organic-inorganic halide perovskite materials. Compared with the monofunctional cation benzylamine hydroiodide (BA) and the nonconjugated bifunctional organic molecule 5-ammonium valeric acid, devices based on AB-MAPbI3 show a good stability and a superior power conversion efficiency of 15.6% with a short-circuit current of 23.4 mA cm-2 , an open-circuit voltage of 0.94 V, and a fill factor of 0.71. The bifunctional conjugated cation not only benefits the growth of perovskite crystals in the mesoporous network, but also facilitates the charge transport. This investigation helps explore new approaches to rational design of novel organic cations for perovskite materials.

17.
Org Lett ; 20(2): 373-376, 2018 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-29303592

RESUMO

This paper reports that cis-TPE dicycles emit strong fluorescence, while the gem dicycles show almost no emission in solution, demonstrating that the free rotation restriction of the double bond at the excited state is the key factor for AIE effects.

18.
Biomed Pharmacother ; 97: 656-666, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29101810

RESUMO

In current study, a series of shikonin derivatives were synthesized and its anticancer activity was evaluated. As a result, PMMB232 showed the best antiproliferation activity with an IC50 value of 3.25±0.35µM. Further, treatment of HeLa cells with a variety of concentrations of target drug resulted in dose-dependent event marked by apoptosis. What's more, the mitochondrial potential (Δym) analysis was consistent with the apoptosis result. In addition, PARP was involved in the progress of apoptosis revealed by western blotting. To identify the detailed role and mechanism of PMMB232 in the progression of human cervical cancer, we detected the expression of HIF-1α and E-cadherin in HeLa cells. Results showed that expression of HIF-1α was downregulated, while E-cadherin protein was upregulated. Meanwhile, glycolysis related protein PDK1 was decreased in HeLa cells. Conversely, the expression of PDH-E1α was upregulated. Docking simulation results further indicate that PMMB232 could be well bound to HIF-1α. Taken together, our data indicate that compound PMMB232 could be developed as a potential anticancer agent.


Assuntos
Antineoplásicos/uso terapêutico , Apoptose/fisiologia , Ácidos Carboxílicos/uso terapêutico , Cumarínicos/uso terapêutico , Subunidade alfa do Fator 1 Induzível por Hipóxia/biossíntese , Naftoquinonas/uso terapêutico , Antineoplásicos/síntese química , Apoptose/efeitos dos fármacos , Ácidos Carboxílicos/síntese química , Cumarínicos/síntese química , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Células HeLa , Humanos , Simulação de Acoplamento Molecular/métodos , Naftoquinonas/síntese química , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/metabolismo
19.
J Am Chem Soc ; 140(3): 1019-1027, 2018 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-29275630

RESUMO

The environmental toxicity of Pb in organic-inorganic hybrid perovskite solar cells remains an issue, which has triggered intense research on seeking alternative Pb-free perovskites for solar applications. Halide perovskites based on group-VA cations of Bi3+ and Sb3+ with the same lone-pair ns2 state as Pb2+ are promising candidates. Herein, through a joint experimental and theoretical study, we demonstrate that Cl-incorporated methylammonium Sb halide perovskites (CH3NH3)3Sb2ClXI9-X show promise as efficient solar absorbers for Pb-free perovskite solar cells. Inclusion of methylammonium chloride into the precursor solutions suppresses the formation of the undesired zero-dimensional dimer phase and leads to the successful synthesis of high-quality perovskite films composed of the two-dimensional layered phase favored for photovoltaics. Solar cells based on the as-obtained (CH3NH3)3Sb2ClXI9-X films reach a record-high power conversion efficiency over 2%. This finding offers a new perspective for the development of nontoxic and low-cost Sb-based perovskite solar cells.

20.
Eur J Med Chem ; 144: 137-150, 2018 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-29268130

RESUMO

Shikonin exhibits powerful anticancer activities for various cancer cells, but its poor solubility and strong toxicity hinder its development as clinical anticancer agent. We previously confirmed that shikonin and its derivatives can disturb mitosis through targeting tubulin. In this study, α-lipoic acid, the naturally-occurring co-factor of pyruvate dehydrogenase (PDH), was introduced into shikonin to design the twin drugs against both mitosis (tubulin) and glycolysis (PDK). 18 kinds of α-lipoic acid shikonin ester derivatives were achieved through three rounds of screening process performed by computer assistant drug design method, being designated as the outstanding compounds. Among them, 1c displayed the most potent cytotoxicity towards cervical cancer cells (HeLa) with an IC50 value of 3.14 ± 0.58 µM and inhibited xenotransplanted tumor growth in a dose-dependent manner. Further pharmacologic study demonstrated that 1c can cause cell cycle arrest in G2/M phase as tubulin polymerization inhibitor. Moreover, it also showed good PDK1 inhibitory activity, promoting PDH activity and forced HeLa cells to process more aerobic metabolism to undergo cell apoptosis. We reported here the first dual inhibitors of tubulin and PDK1 based on shikonin. It may form a basis for shikonin optimization through twin drug design framework for the discovery of new and potent shikonin derivatives in the study of targeted cancer therapy.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Naftoquinonas/química , Naftoquinonas/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologia , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Desenho de Drogas , Glicólise/efeitos dos fármacos , Células HeLa , Humanos , Mitose/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Tubulina (Proteína)/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA