RESUMO
Materials for radiation detection are critically important and urgently demanded in diverse fields, starting from fundamental scientific research to medical diagnostics, homeland security, and environmental monitoring. Low-dimensional halides (LDHs) exhibiting efficient self-trapped exciton (STE) emission with high photoluminescence quantum yield (PLQY) have recently shown a great potential as scintillators. However, an overlooked issue of exciton-exciton interaction in LDHs under ionizing radiation hinders the broadening of its radiation detection applications. Here, we demonstrate an exceptional enhancement of exciton-harvesting efficiency in zero-dimensional (0D) Cs3Cu2I5:Tl halide single crystals by forming strongly localized Tl-bound excitons. Because of the suppression of non-radiative exciton-exciton interaction, an excellent α/ß pulse-shape-discrimination (PSD) figure-of-merit (FoM) factor of 2.64, a superior rejection ratio of 10-9, and a high scintillation yield of 26 000 photons MeV-1 under 5.49 MeV α-ray are achieved in Cs3Cu2I5:Tl single crystals, outperforming the commercial ZnS:Ag/PVT composites for charged particle detection applications. Furthermore, a radiation detector prototype based on Cs3Cu2I5:Tl single crystal demonstrates the capability of identifying radioactive 220Rn gas for environmental radiation monitoring applications. We believe that the exciton-harvesting strategy proposed here can greatly boost the applications of LDHs materials.
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Species from east China belonging to the subgenus Curtonotus were studied, resulting in the description of a new species, Amara (Curtonotus) beijingensissp. nov. The type locality is Xiaolongmen Forest Park in Beijing. All the known macropterous Curtonotus species from eastern China are reviewed and for each species taxonomical notes, illustrations, and new provincial records are noted. An improved key for their identification is provided as well.
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The simultaneous reduction of Cr(VI) and sequestration of the resulting Cr(III) in one process is highly desirable as a cost-effective and environmental-friendly approach for the decontamination of Cr(VI)-polluted wastewater. However, most of the existing adsorptive materials are only effective in low pH environments (pH = 1-3), severely restricting the adsorption efficiency and cost effectiveness. Herein, we proposed a chitosan-based magnetic porous microsphere (PPy@PMCS) for simultaneous Cr(VI) reduction and Cr(III) sequestration in a wide pH range. Benefiting from its abundant interaction sites, Cr(VI) was effectively adsorbed on the surface and then immediately reduced to Cr(III) with much lower toxicity. Most importantly, the resulting Cr(III) was in-situ sequestrated by the complexation of chitosan matrix. As a result, PPy@PMCS exhibited a maximum Cr(VI) adsorption capacity of 330.42 mg/g at pH 2.0 and an adsorption capacity of 167.82 mg/g even at near neutral pH (6.0), which is superior to most reported adsorbents. Furthermore, the exhausted PPy@PMCS can be rapidly separated from solutions under an external magnetic field and facilely regenerated. The proposed novel biopolymer-based material shows great application potentials in wastewater treatment.
Assuntos
Quitosana , Poluentes Químicos da Água , Cinética , Cromo , Biopolímeros , Adsorção , Concentração de Íons de Hidrogênio , Campos MagnéticosRESUMO
The Pterostichuspulcher species group of the subgenus Orientostichus Sciaky & Allegro is defined for P.pulcher Sciaky & Allegro and six new allied species. All seven species of this group are revised on morphological characters. Six new species are described from south of Sichuan province, China: P.pemphissp. nov. (type locality: Shuihaizi, Puge county, 27.33°N, 102.45°E), P.orbicollissp. nov. (Longzhoushan, Huili county, 26.79°N, 102.20°E), P.leosp. nov. (Shizishan, Jinyang county, 27.88°N, 103.23°E), P.liyuanisp. nov. (Luojishan, Puge county, 27.58°N, 102.39°E), P.condylussp. nov. (Yele, Mianning county, 28.96°N, 102.16°E), P.jialinisp. nov. (Jiamashi, Huidong county, 26.81°N, 102.68°E). Tritrichischinensis Jedlicka, syn. nov., a species previously misplaced in the subgenus Orientostichus, is excluded from the genus Pterostichus and confirmed to be a junior synonym of Synuchusnitidusreticulatus Lindroth, 1956.
RESUMO
Group IB chalcogenides, as promising thermoelectric materials, have ultralow thermal transport. Here, we propose a peculiar intrinsic B2 phonon mode that includes the in-plane rotational and stretching vibrations of metal atoms in two-dimensional A2IBSe1/2Te1/2 (AIB = Cu, Ag, or Au). The B2 mode is sensitive to the metal-atom mass, temperature, and strain for effectively tuning the lattice thermal conductivity. The in-plane stretching vibration leads to an unexpected increase in the lattice thermal conductivity from Cu to Ag and to Au systems, in contrast to Keyes' theory. The s(I) phase can be stabilized by the temperature-hardened B2 mode to reduce the lattice thermal conductivity, following the â¼T-0.59 instead of the traditional â¼T-1 trend. The s(II)-to-s(I) phase transition is driven by the strain-softened B2 mode to greatly enhance thermal transport via weakening the anharmonicity. Our work establishes the relationship of tunable intrinsic phonon mode versus thermal transport in two-dimensional group IB chalcogenides.
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The present contribution revises the genus Parena Motschulsky, 1860, a group of arboreal carabid beetles with 46 recognized species, distributed in Tropical Asia, Sub-Saharan Africa, and the north and east coastal Australasia. We re-evaluate the infrageneric taxonomy of the genus and redefine three subgenera: Parena s. str., Bothynoptera Schaum, 1863 and Crossoglossa Chaudoir, 1872, based on the morphological characters of external features, male genitalia and female ovipositors. Under these three subgenera, we define 14 species groups to contain all known species. Keys for the identification of all subgenera, species groups, and species are provided, along with diagnostic characters, included species, geographical distribution, brief discussion on monophyly and relationships for each subgenus and species group, ample species descriptions, distribution maps, habitus images, and genitalia illustrations. The previous alpha-taxonomy of the genus Parena is defective, and several species were described without genital morphological comparisons with their real adelphotaxon. Based on careful examination of a large amount of type materials, we propose 19 new synonyms: P. rufotestacea Jedlicka, 1934, as a junior synonym of P. cavipennis (Bates, 1873); P. perforata (Bates, 1873), P. nepalensis Kirschenhofer, 1994, and P. kunmingensis Kirschenhofer, 1996, as junior synonyms of P. dorsigera (Schaum, 1863); P. wrasei Kirschenhofer, 2006, as a junior synonym of P. kurosai Habu, 1967; P. nantouensis Kirschenhofer, 1996 and P. kataevi Kirschenhofer, 2006, as junior synonyms of P. tesari (Jedlicka, 1951); P. yunnana Kirschenhofer, 1994, as a junior synonym of P. shapingensis Xie & Yu, 1993; P. albomaculata Habu, 1979, as a junior synonym of P. malaisei (Andrewes, 1947); P. koreana Kirschenhofer, 1994, as a junior synonym of P. monostigma (Bates, 1873); P. phongsalyensis Kirschenhofer, 2011, as a junior synonym of P. quadrisignata Mateu, 1977; P. sellata (Heller, 1921), P. hastata (Heller, 1921), P. sellatoides (Jedlicka, 1940), P. fasciata var. unicolor Louwerens, 1949, and P. sumatrana Kirschenhofer, 2011, as junior synonyms of P. fasciata (Chaudoir, 1872); P. nigrolineata nipponensis Habu, 1964 and P. schillhammeri Kirschenhofer, 2006, as junior synonyms of P. nigrolineata (Chaudoir, 1852); and P. alluaudi Jeannel, 1949, as a junior synonym of P. madagascariensis (Alluaud, 1917). Furthermore, the specific status of P. scutata (Alluaud, 1917) is resurrected from synonym with P. plagiata Motschulsky, 1864. Parena sticta (Andrewes, 1947) is excluded from Parena and a new combination is suggested: Peliocypas stictus (Andrewes, 1947) comb. nov. A total of eight new species are described: P. (Crossoglossa) sciakyi sp. nov. (type locality: Guadalcanal, Solomon Islands), P. (Bothynoptera) heteronycha sp. nov. (type locality: Houaphan, Laos), P. (Bothynoptera) emarginata sp. nov. (type locality: Muli, Sichuan, China), P. (Bothynoptera) gonggaica sp. nov. (type locality: Hailuogou, Sichuan, China), P. (Bothynoptera) triguttata sp. nov. (type locality: Kangding, Sichuan, China), P. (Parena) picipes sp. nov. (type locality: Trus Madi, Borneo), P. (Parena) fulva sp. nov. (type locality: Dodoma, Tanzania), and P. (Parena) ruficornis sp. nov. (type locality: Lobaye, the Central African Republic). Several of these new species are very rare in collections, with four of them known from females only.
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Besouros , Masculino , Feminino , Animais , TanzâniaRESUMO
The first total syntheses of Lycopodium alkaloids phleghenrines A and C have been accomplished in 19 and 18 steps, respectively, relying on three (hetero)-Diels-Alder ([4 + 2]) cycloaddition reactions to forge the cyclic molecular backbone and two ring-expansion reactions to manipulate the ring size. A chiral precursor is synthesized through an auxiliary controlled Diels-Alder reaction, rendering the asymmetric synthesis accessible. The established strategy provides a general approach to the relevant novel Lycopodium alkaloids.
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The first total syntheses of (±)-catellatolactams A and B, two novel ansamacrolactams, are described in 5 and 8 steps, respectively. The strategy relies on an amidation reaction to couple the acylated Meldrum's acid and an aryl amine, a regioselective C-H insertion to construct the γ-lactam moiety, and an RCM reaction to forge the macrocycles with E-olefin. This concise and scalable synthesis provided over 200 mg of the target molecules.
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The total synthesis of the indole alkaloid (-)-andranginine has been achieved in 10 steps. Key reactions of the synthesis include a nucleophilic addition of acetylenyl anion to chiral N-sulfinyl imine, an intramolecular N-alkylation reaction to close the C ring, and a dienyne metathesis cascade reaction to construct the DE rings. Meanwhile, 16-epi-(-)-andranginine was also obtained with the developed strategy.
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Iminas , Alcaloides Indólicos , Estrutura Molecular , EstereoisomerismoRESUMO
A total of eleven species and two subspecies are recognized within the Chinese endemic genus Straneostichus Sciaky, 1994 (Carabidae: Pterostichini), including three new species described in the present paper: Straneostichus politus sp. nov. (Sichuan: Wolong), Straneostichus liupanensis sp. nov. (Ningxia: Liupanshan) and Straneostichus ganqingensis sp. nov. (Qinghai: Mengda and Gansu: Dangchang). Taxonomical notes and new distribution records for all the known species are provided, along with an updated key to the species of Straneostichus.
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Besouros , Distribuição Animal , Estruturas Animais , Animais , Tamanho do ÓrgãoRESUMO
The skeleton of lucidumone was constructed through oxidative dearomatization/intramolecular Diels-Alder reaction, Cu-mediated remote C-H hydroxylation, allyl oxidation, acid-promoted dynamic kinetic resolution cyclization, and benzylic oxidation.
Assuntos
Esqueleto , Ciclização , Reação de Cicloadição , Estrutura Molecular , OxirreduçãoRESUMO
It is reported herein that by exploiting the commonly shared bicyclic decahydroquinoline motif, a gold-catalyzed enamide-alkyne cycloisomerization reaction is developed to access tricyclic cores in a simple way. These tricyclic cores further serve as an advanced platform for the divergent enantioselective collective total syntheses of five Lycopodium alkaloids, belonging to three different structural types, in a concise and protecting-group-free fashion. The key transformations in the second phase include: 1)â a transannular reductive Heck cyclization for installation of the azepane ring in fawcettidine, fawcettimine, and lycoposerramineâ Q; 2)â a domino Mukaiyama hydration/Grob fragmentation process for construction of the ten-membered lactam system in phlegmariurineâ B; 3)â a Fukuyama one-pot protocol for the construction of the 2-pyridone motif in lycoposerramineâ R. The newly developed strategy is expected to pave the way for the synthesis of other structurally related Lycopodium alkaloids.
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Alcaloides , Lycopodium , Alcaloides/química , Ciclização , Lycopodium/química , Estrutura Molecular , EstereoisomerismoRESUMO
Background: Pareuryaptus is a genus of Carabidae containing 18 species and one subspecies, distributed mainly in the Oriental Region. However, only one species and one subspecies were recorded from China before the present study. New information: Four species and one subspecies of Pareuryaptus are reported from China with three of them newly recorded: Pareuryaptusadoxus (Tschitschérine) from Yunnan; Pareuryaptusexiguus Dubault, Lassalle & Roux from Guangxi; and Pareuryaptusluangphabangensis Kirschenhofer from Yunnan. Moreover, the male of Pareuryaptusexiguus Dubault, Lassalle & Roux is firstly described and a key to all known Chinese species is provided.
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The Chinese species of subgenus Koreonialoe Park & Kwon, 1996 of the genus Pterostichus are revised, including four species from the eastern part of Jilin and Liaoning provinces. Two new species are described: Pterostichus (Koreonialoe) micropoidessp. nov. (type locality: Jilin, Changbai county), and Pterostichus (Koreonialoe) tetralobatussp. nov. (type locality: Liaoning, Xiuyan county). Pterostichus (Koreonialoe) bellatrix (Tschitschérine) is newly recorded from China (Jilin). The subgenus Koreonialoe is classified into two groups on account of their differences on the endophallus, and all Chinese species accord with the microps group defined herein. A key to all six species in the microps group is provided.
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The design of an angular array of electron time-of-flight (eToF) spectrometers is reported, intended for non-invasive spectral, temporal, and polarization characterization of single shots of high-repetition rate, quasi-continuous, short-wavelength free-electron lasers (FELs) such as the LCLSâ II at SLAC. This array also enables angle-resolved, high-resolution eToF spectroscopy to address a variety of scientific questions on ultrafast and nonlinear light-matter interactions at FELs. The presented device is specifically designed for the time-resolved atomic, molecular and optical science endstation (TMO) at LCLSâ II. In its final version, the spectrometer comprises up to 20 eToF spectrometers aligned to collect electrons from the interaction point, which is defined by the intersection of the incoming FEL radiation and a gaseous target. The full composition involves 16 spectrometers forming a circular equiangular array in the plane normal to the X-ray propagation and four spectrometers at 54.7° angle relative to the principle linear X-ray polarization axis with orientations in the forward and backward direction of the light propagation. The spectrometers are capable of independent and minimally chromatic electrostatic lensing and retardation, in order to enable simultaneous angle-resolved photo- and Auger-Meitner electron spectroscopy with high energy resolution. They are designed to ensure an energy resolution of 0.25â eV across an energy window of up to 75â eV, which can be individually centered via the adjustable retardation to cover the full range of electron kinetic energies relevant to soft X-ray methods, 0-2â keV. The full spectrometer array will enable non-invasive and online spectral-polarimetry measurements, polarization-sensitive attoclock spectroscopy for characterizing the full time-energy structure of SASE or seeded LCLSâ II pulses, and support emerging trends in molecular-frame spectroscopy measurements.
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Two new species of the carabid genus Deltomerodes are described from Xizang (China): D. ovicollis sp. nov. (type locality: Doxong La, Mêdog) and D. conaensis sp. nov. (type locality: Rama La, Cona). The new species are amply described, illustrated, and their distributions are mapped. An updated key to all eight known Chinese Deltomerodes species is provided.
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BACKGROUND: Avapritinib, a potent inhibitor of KIT and platelet-derived growth factor receptor A (PDGFRA) tyrosine kinases, has demonstrated unprecedented clinical activity in PDGFRA D842V-mutant gastrointestinal stromal tumors (GIST). METHODS: This retrospective analysis compared efficacy of avapritinib in patients enrolled in the NAVIGATOR phase 1 trial (NCT02508532) with the efficacy of other tyrosine kinase inhibitors (TKIs) in patients with unresectable/metastatic PDGFRA D842V-mutant GIST enrolled in a retrospective natural history study (Study 1002). The primary endpoint was overall survival (OS) from the start of reference treatment (avapritinib for NAVIGATOR patients or first-line TKI for treatment of unresectable/metastatic GIST for Study 1002 patients); the secondary endpoint was progression-free survival (PFS). Adjusted Kaplan-Meier survival curves were compared by Cox regression. RESULTS: Fifty-six (NAVIGATOR) and 19 (Study 1002) patients with PDGFRA D842V-mutant GIST were evaluated; of the 56 patients from NAVIGATOR, a subgroup of patients treated with either 300 mg (recommended phase 2 dose) or 400 mg (maximum tolerated dose) avapritinib starting dose (n = 38) were analyzed separately. Patient characteristics were adjusted for imbalances by propensity score between the study groups. Inverse probability of treatment weighting-adjusted Kaplan-Meier analysis of OS showed median OS was not reached for NAVIGATOR patients treated with any of the avapritinib doses tested and was 12.6 months for Study 1002 patients; OS rate at 6/48 months was 100%/63% in NAVIGATOR and 56%/17% in Study 1002 (P = 0.0001). In the 300/400 mg subgroup, adjusted OS rates at 6/36 months were 100%/73 and 68%/20% in Study 1002 (P = 0.0016). Adjusted median PFS was 29.5 months in NAVIGATOR and 3.4 months in Study 1002. CONCLUSIONS: In this indirect, retrospective analysis, avapritinib demonstrated more durable survival outcomes compared with other TKIs in patients with unresectable/metastatic PDGFRA D842V-mutant GIST. TRIAL REGISTRATION: The NAVIGATOR trial was registered at ClinicalTrials.gov as per July 2015, Identifier: NCT02508532 .
Assuntos
Tumores do Estroma Gastrointestinal/tratamento farmacológico , Inibidores de Proteínas Quinases/administração & dosagem , Pirazóis/administração & dosagem , Pirróis/administração & dosagem , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Triazinas/administração & dosagem , Ensaios Clínicos Fase I como Assunto , Feminino , Tumores do Estroma Gastrointestinal/genética , Tumores do Estroma Gastrointestinal/mortalidade , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Intervalo Livre de Progressão , Inibidores de Proteínas Quinases/efeitos adversos , Pirazóis/efeitos adversos , Pirróis/efeitos adversos , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Estudos Retrospectivos , Triazinas/efeitos adversosRESUMO
A new species of the genus Megischus Brullé, 1846, Megischus kuafu Ge & Tan, sp. nov., is described and illustrated from Guizhou Province, China. The key to all four species from China is included. A distribution map of the Chinese species is added.
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BACKGROUND: The family Pieridae is a large group of butterflies which plays an important role in evolutionary biology and contains many potential pests (Courtney 1986). Pieridae is a cosmopolitan family while the tropics harbour higher species richness. In a very recent expedition to the Chinese-Indian border area in Tibet Autonomous Region, a migratory species, Belenois aurota (Fabricius, 1793), was discovered for the first time, which comprises the first record of the genus Belenois in China and the highest altitude record of this species. NEW INFORMATION: The species B. aurota (Fabricius, 1793) is the first record of the genus Belenois from China. The specimen was collected at an altitude of about 3,000 m in Tibet Autonomous Region. Relevant details are presented for the species.
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The genus Laemostenus is recorded from China for the first time, and two new species are described: L. (Pristonychus) zhentangensissp. nov. (type locality: Dinggyê County, Xizang), and L. (P.) zhamensissp. nov. (type locality: Nyalam County, Xizang). The relationships of these new species are briefly discussed.