Palladium-catalyzed difluoromethylation of heteroaryl chlorides, bromides and iodides.

A palladium-catalyzed difluoromethylation of a series of heteroaryl chlorides, bromides and iodides under mild conditions is described. A wide range of heteroaryl halides such as pyridyl, pyrimidyl, pyrazyl, funanyl, thienyl, pyazolyl, imidazolyl, thiazolyl, and oxazolyl halides were efficiently difluoromethylated, thus providing medicinal chemists an alternative choice for the preparation of drug candidates with the difluoromethylated heteroarene unit

Effects of a Cardiotonic Medicine Danshen Pills, on Cognitive Ability and Expression of PSD-95 in a Vascular Dementia Rat Model

A widely used Chinese cardiotonic proprietary medicine, compound Danshen dripping pills (CDDP, Fufang Danshen Diwan) has also begun to be used for treatment of vascular dementia (VaD). We tried to explore the mechanism of CDDP action in this case. A VaD experimental model was built in rats by bilateral ligation of the common carotid arteries. The cognitive ability of experimental animals was evaluated in the Morris water maze test. Synaptic ultrastructural changes in the hippocampus were detected by transmission electron microscopy; expression of PSD-95 mRNA in the hippocampus was examined using hybridization in situ. The latter index (mRNA expression) in the VaD group was significantly lower than those in the CDDP and shamoperated groups (P < 0.05). CDDP treatment considerably improved disturbed ultrastructural synaptic characteristics in the hippocampus of VaD rats. The mean escape latency in the Morris water maze test was significantly shorter in CDDP-treated VaD rats, compared with that those of the VD group (P < 0.05). In the CDDP group compared to the VaD one, escape strategies improved from edge and random searches to more linear swim pathway (P < 0.05). Thus, decreasing expression of PSD-95 plays an important role in the pathogenesis of VaD. CDDP treatment improves the learning and memory ability of VaD rats by improving neural synaptic ultrastructural characteristics and increasing expression of PSD-95 mRNA in the hippocampus.Широко вживаний у Китаї патентований кардіотонічний засіб «складні пілюлі Даншен» (CDDP) почав також використовуватися для лікування васкулярної деменції (ВД). Ми досліджували можливі механізми дії цього засобу в даному аспекті. ВД моделювали у щурів, застосовуючи білатеральну перев’язку загальних сонних артерій. Когнітивні здатності експериментальних тварин оцінювали в тесті водного лабіринту Морріса. Ультраструктурні зміни синаптичних утворень у гіпокампі спостерігали, використовуючи трансмісійну електронну мікроскопію. Експресію мРНК білка PSD-95 у гіпокампі оцінювали із застосуванням методики гібридизації in situ. Останній показник (експресія мРНК) у щурів групи ВД був вірогідно нижчим, ніж у тварин контрольної групи та щурів із ВД, лікованих за допомогою CDDP. Середня затримка реакції уникання у тварин групи ВД істотно перевищувала відповідне значення в групі CDDP (P < 0.05). Стратегії уникання в останній групі були вірогідно кращими, ніж у групі ВД (збільшувалася пропорція лінійних маршрутів порівняно з «крайовими» та випадковими; P < 0.05). Зроблено висновок, що зниження експресії PSD-95 відіграє важливу роль у патогенезі ВД. Лікувальний ефект CDDP забезпечує покращення пам’яті та здатності до навчання у щурів з ВД; цей ефект опосередковується покращенням ультраструктурних показників синаптичних структур та збільшенням експресії мРНК білка PSD-95 у гіпокампі

Hyperspectral LiDAR-Based Plant Spectral Profiles Acquisition : Performance Assessment and Results Analysis

In precision agriculture, efficient fertilization is one of the most important pursued goals. Vegetation spectral profiles and the corresponding spectral parameters are usually employed for vegetation growth status indication, i.e., vegetation classification, bio-chemical content mapping, and efficient fertilization guiding. In view of the fact that the spectrometer works by relying on ambient lighting condition, hyperspectral/multi-spectral LiDAR (HSL/MSL) was invented to collect the spectral profiles actively. However, most of the HSL/MSL works with the wavelength specially selected for specific applications. For precision agriculture applications, a more feasible HSL capable of collecting spectral profiles at wide-range spectral wavelength is necessary to extract various spectral parameters. Inspired by this, in this paper, we developed a hyperspectral LiDAR (HSL) with 10 nm spectral resolution covering 500~1000 nm. Different vegetation leaf samples were scanned by the HSL, and it was comprehensively assessed for wide-range wavelength spectral profiles acquirement, spectral parameters extraction, vegetation classification, and the laser incident angle effect. Specifically, three experiments were carried out: (1) spectral profiles results were compared with that from a SVC spectrometer (HR-1024, Spectra Vista Corporation); (2) the extracted spectral parameters from the HSL were assessed, and they were employed as the input features of a support vector machine (SVM) classifier with multiple labels to classify the vegetation; (3) in view of the influence of the laser incident angle on the HSL reflected laser intensities, we analyzed the laser incident angle effect on the spectral parameters values. The experimental results demonstrated the developed HSL was more feasible for acquiring spectral profiles with wide-range wavelength, and spectral parameters and vegetation classification results also indicated its great potentials in precision agriculture application

Analysis and Radiometric Calibration for Backscatter Intensity of Hyperspectral LiDAR Caused by Incident Angle Effect

Hyperspectral LiDAR (HSL) is a new remote sensing detection method with high spatial and spectral information detection ability. In the process of laser scanning, the laser echo intensity is affected by many factors. Therefore, it is necessary to calibrate the backscatter intensity data of HSL. Laser incidence angle is one of the important factors that affect the backscatter intensity of the target. This paper studied the radiometric calibration method of incidence angle effect for HSL. The reflectance of natural surfaces can be simulated as a combination of specular reflection and diffuse reflection. The linear combination of the Lambertian model and Beckmann model provides a comprehensive theory that can be applied to various surface conditions, from glossy to rough surfaces. Therefore, an adaptive threshold radiometric calibration method (Lambertian-Beckmann model) is proposed to solve the problem caused by the incident angle effect. The relationship between backscatter intensity and incident angle of HSL is studied by combining theory with experiments, and the model successfully quantifies the difference between diffuse and specular reflectance coefficients. Compared with the Lambertian model, the proposed model has higher calibration accuracy, and the average improvement rate to the samples in this study was 22.67%. Compared with the results before calibration with the incidence angle of less than 70 degrees, the average improvement rate of the Lambertian-Beckmann model was 62.26%. Moreover, we also found that the green leaves have an obvious specular reflection effect near 650-720 nm, which might be related to the inner microstructure of chlorophyll. The Lambertian-Beckmann model was more helpful to the calibration of leaves in the visible wavelength range. This is a meaningful and a breakthrough exploration for HSL.Peer reviewe

Review on Active and Passive Remote Sensing Techniques for Road Extraction

Digital maps of road networks are a vital part of digital cities and intelligent transportation. In this paper, we provide a comprehensive review on road extraction based on various remote sensing data sources, including high-resolution images, hyperspectral images, synthetic aperture radar images, and light detection and ranging. This review is divided into three parts. Part 1 provides an overview of the existing data acquisition techniques for road extraction, including data acquisition methods, typical sensors, application status, and prospects. Part 2 underlines the main road extraction methods based on four data sources. In this section, road extraction methods based on different data sources are described and analysed in detail. Part 3 presents the combined application of multisource data for road extraction. Evidently, different data acquisition techniques have unique advantages, and the combination of multiple sources can improve the accuracy of road extraction. The main aim of this review is to provide a comprehensive reference for research on existing road extraction technologies.Peer reviewe

The progress of TMT Laser Guide Star Facility

The Laser Guide Star Facility (LGSF) is responsible for generating the artificial laser guide stars required by the TMT Laser Guide Star (LGS) AO systems. The LGSF uses multiple sodium lasers to generate and project several LGS asterisms from a laser launch telescope located behind the TMT secondary mirror. The LGSF includes 3 main subsystems: (1) the laser system, (2) the beam transfer optics (BTO) system, (3) the associated laser safety system. At present, the LGSF is in the preliminary design phase. During this phase, the laser launch telescope trade study, Beam transfer optical path trade study are compared carefully, and some critical components prototypes have been carried out to verify the requirements, such as the polarization status control and test, the Fast Steer Mirror (FSM) prototype test

Contrasting Soil Bacterial Community, Diversity, and Function in Two Forests in China

Bacteria are the highest abundant microorganisms in the soil. To investigate bacteria community structures, diversity, and functions, contrasting them in four different seasons all the year round with/within two different forest type soils of China. We analyzed soil bacterial community based on 16S rRNA gene sequencing via Illumina HiSeq platform at a temperate deciduous broad-leaved forest (Baotianman, BTM) and a tropical rainforest (Jianfengling, JFL). We obtained 51,137 operational taxonomic units (OTUs) and classified them into 44 phyla and 556 known genera, 18.2% of which had a relative abundance &gt;1%. The composition in each phylum was similar between the two forest sites. Proteobacteria and Acidobacteria were the most abundant phyla in the soil samples between the two forest sites. The Shannon index did not significantly differ among the four seasons at BTM or JFL and was higher at BTM than JFL in each season. The bacteria community at both BTM and JFL showed two significant (P &lt; 0.05) predicted functions related to carbon cycle (anoxygenic photoautotrophy sulfur oxidizing and anoxygenic photoautotrophy) and three significant (P &lt; 0.05) predicted functions related to nitrogen cycle (nitrous denitrificaton, nitrite denitrification, and nitrous oxide denitrification). We provide the basis on how changes in bacterial community composition and diversity leading to differences in carbon and nitrogen cycles at the two forests

The progress of TMT Laser Guide Star Facility

The Laser Guide Star Facility (LGSF) is responsible for generating the artificial laser guide stars required by the TMT Laser Guide Star (LGS) AO systems. The LGSF uses multiple sodium lasers to generate and project several LGS asterisms from a laser launch telescope located behind the TMT secondary mirror. The LGSF includes 3 main subsystems: (1) the laser system, (2) the beam transfer optics (BTO) system, (3) the associated laser safety system. At present, the LGSF is in the preliminary design phase. During this phase, the laser launch telescope trade study, Beam transfer optical path trade study are compared carefully, and some critical components prototypes have been carried out to verify the requirements, such as the polarization status control and test, the Fast Steer Mirror (FSM) prototype test