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1.
Opt Express ; 32(10): 18366-18378, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38858994

ABSTRACT

Mode-pairing quantum key distribution (MP-QKD) holds great promise for the practical implementation of QKD in the near future. It combines the security advantages of measurement device independence while still being capable of breaking the Pirandola-Laurenza-Ottaviani-Banchi bound without the need for highly demanding phase-locking and phase-tracking technologies for deployment. In this work, we explore optimization strategies for MP-QKD in a wavelength-division multiplexing scenario. The simulation results reveal that incorporation of multiple wavelengths not only leads to a direct increase in key rate but also enhances the pairing efficiency by employing our novel pairing strategies among different wavelengths. As a result, our work provides a new avenue for the future application and development of MP-QKD.

2.
Curr Microbiol ; 80(5): 171, 2023 Apr 06.
Article in English | MEDLINE | ID: mdl-37024713

ABSTRACT

Dengue remains a public health issue worldwide. Similar to chronic infectious diseases, stimulation of cytokine production is not enough to drive immune effector cells for effective virus clearance. One possible mechanism is the virus induces a large number of negative stimulatory cytokines inhibiting immune response. Interleukin 37 (IL-37) plays a crucial regulatory role in infection and immunity, inhibits innate and adaptive immunity as an anti-inflammatory cytokine by inhibiting proinflammatory mediators and pathways. To date, there are few studies reporting correlations between dengue fever (DF) and IL-37. In this study we found that the serum IL-37b and IL-37b-producing monocytes in patients were significantly increased in DF patients. A majority of the IL-37b produced by DF patients was produced by monocytes, not lymphocytes. Increased levels of IL-6, IL-10, and IFN-α were also found in DF patients. However, we failed to detect IL-1ß, IL-17A and TNF-α in plasma, because of off-target. In our study, there was no relation between IL-6, IL-10, and IFN-α expressions and IL-37b in serum (P > 0.05). The IL-37b-producing monocytes were negatively correlated with the level of IFN-α in serum and platelet count, and positively correlated with lymphocytes percentage (P < 0.05, respectively). Additionally, serum DENV nonstructural protein 1 levels were positively correlated with monocytes percentages (P < 0.05). Our data represents findings for IL-37b expression and its potential mechanisms in DF patients' immune response.


Subject(s)
Dengue Virus , Dengue , Humans , Interleukin-10 , Dengue Virus/physiology , Interleukin-6 , Viral Load , Cytokines
3.
Zhongguo Zhong Yao Za Zhi ; 48(9): 2500-2511, 2023 May.
Article in Zh | MEDLINE | ID: mdl-37282879

ABSTRACT

This study aimed to elucidate the effect and underlying mechanism of Bovis Calculus in the treatment of ulcerative colitis(UC) through network pharmacological prediction and animal experimental verification. Databases such as BATMAN-TCM were used to mine the potential targets of Bovis Calculus against UC, and the pathway enrichment analysis was conducted. Seventy healthy C57BL/6J mice were randomly divided into a blank group, a model group, a solvent model(2% polysorbate 80) group, a salazosulfapyridine(SASP, 0.40 g·kg~(-1)) group, and high-, medium-, and low-dose Bovis Calculus Sativus(BCS, 0.20, 0.10, and 0.05 g·kg~(-1)) groups according to the body weight. The UC model was established in mice by drinking 3% dextran sulfate sodium(DSS) solution for 7 days. The mice in the groups with drug intervention received corresponding drugs for 3 days before modeling by gavage, and continued to take drugs for 7 days while modeling(continuous administration for 10 days). During the experiment, the body weight of mice was observed, and the disease activity index(DAI) score was recorded. After 7 days of modeling, the colon length was mea-sured, and the pathological changes in colon tissues were observed by hematoxylin-eosin(HE) staining. The levels of tumor necrosis factor-α(TNF-α), interleukin-1ß(IL-1ß), interleukin-6(IL-6), and interleukin-17(IL-17) in colon tissues of mice were detected by enzyme-linked immunosorbent assay(ELISA). The mRNA expression of IL-17, IL-17RA, Act1, TRAF2, TRAF5, TNF-α, IL-6, IL-1ß, CXCL1, CXCL2, and CXCL10 was evaluated by real-time polymerase chain reaction(RT-PCR). The protein expression of IL-17, IL-17RA, Act1, p-p38 MAPK, and p-ERK1/2 was investigated by Western blot. The results of network pharmacological prediction showed that Bovis Calculus might play a therapeutic role through the IL-17 signaling pathway and the TNF signaling pathway. As revealed by the results of animal experiments, on the 10th day of drug administration, compared with the solvent model group, all the BCS groups showed significantly increased body weight, decreased DAI score, increased colon length, improved pathological damage of colon mucosa, and significantly inhibited expression of TNF-α,IL-6,IL-1ß, and IL-17 in colon tissues. The high-dose BCS(0.20 g·kg~(-1)) could significantly reduce the mRNA expression levels of IL-17, Act1, TRAF2, TRAF5, TNF-α, IL-6, IL-1ß, CXCL1, and CXCL2 in colon tissues of UC model mice, tend to down-regulate mRNA expression levels of IL-17RA and CXCL10, significantly inhibit the protein expression of IL-17RA,Act1,and p-ERK1/2, and tend to decrease the protein expression of IL-17 and p-p38 MAPK. This study, for the first time from the whole-organ-tissue-molecular level, reveals that BCS may reduce the expression of pro-inflammatory cytokines and chemokines by inhibiting the IL-17/IL-17RA/Act1 signaling pathway, thereby improving the inflammatory injury of colon tissues in DSS-induced UC mice and exerting the effect of clearing heat and removing toxins.


Subject(s)
Colitis, Ulcerative , Mice , Animals , Colitis, Ulcerative/drug therapy , Colitis, Ulcerative/genetics , Colitis, Ulcerative/metabolism , Tumor Necrosis Factor-alpha/metabolism , Interleukin-6/metabolism , Interleukin-17/genetics , Interleukin-17/metabolism , Interleukin-17/pharmacology , TNF Receptor-Associated Factor 2/metabolism , TNF Receptor-Associated Factor 2/pharmacology , TNF Receptor-Associated Factor 5/metabolism , Mice, Inbred C57BL , Signal Transduction , Colon , p38 Mitogen-Activated Protein Kinases/metabolism , RNA, Messenger/metabolism , Dextran Sulfate/adverse effects , Dextran Sulfate/metabolism , Disease Models, Animal
4.
Faraday Discuss ; 233(0): 33-43, 2022 04 05.
Article in English | MEDLINE | ID: mdl-34913454

ABSTRACT

Electrochemical measurements at the single entity level provide ultra-sensitive tools for the precise diagnosis and understanding of basic biological and chemical processes. By decoding current signatures, single-entity electrochemistry provides abundant information on charges, sizes, shapes, catalytic performances and compositions. The accuracy of single-entity electrochemistry highly relies on advanced instrumentation to achieve the amperometric resolution at the sub-picoampere level and the temporal resolution at the sub-microsecond level. Currently, it is still a challenge for paralleling amplifiers to allow low-noise and high bandwidth single-entity electrochemical measurements. Herein, we developed a low-noise four-channel electrochemical instrumentation that integrates an Au electrode array with amplifiers in the circuit board. With this amplifier array, we achieved a high bandwidth (>100 kHz) electrochemical measurement. The further practical experiments proved the capability of this amplifier array system in acquiring transient signals from both single-molecule detection with an aerolysin nanopore and single Pt nanoparticle catalysis during the dynamic collision process. Paired with appropriate microfluidic array systems, our instrumentation will enable an extraordinarily high-throughput feature for single-entity sensing.


Subject(s)
Nanopores , Catalysis , Electrochemistry , Electrodes , Nanotechnology
5.
Zhongguo Zhong Yao Za Zhi ; 47(11): 3038-3048, 2022 Jun.
Article in Zh | MEDLINE | ID: mdl-35718528

ABSTRACT

Based on the brain-gut axis, the present study investigated the effect of Huanglian Houpo Decoction(HLHPD) in the treatment of ulcerative colitis(UC) and explored the mechanism in the regulation of 5-hydroxytryptamine(5-HT), substance P(SP), and vasoactive intestinal peptide(VIP) using modern technologies and molecular docking. Sixty male C57 BL/6 J mice were randomly divided into a blank control group, a model group, a sulfasalazine(SASP) group, and high-(5.00 g·kg~(-1)), medium-(2.50 g·kg~(-1)), and low-dose(1.25 g·kg~(-1)) HLHPD groups. The UC model was induced by oral administration of water containing 3% dextran sulfate sodium salt(DSS) in mice except those in the blank control group. After HLHPD was administered for 10 days, the mice were sacrificed for sample collection. Morphological changes of colon tissues were observed by HE staining. The expression of 5-HT, SP, VIP, tumor necrosis factor α(TNF-α), interleukin-6(IL-6), and interleukin-1ß(IL-1ß) in the hypothalamus, serum, and colon was determined by the enzyme-linked immunosorbent assay(ELISA). The expression of tryptophan hydroxylase 1(TPH1), SP, and VIP in colon tissues was evaluated by immunohistochemistry. The expression of brain-gut peptide receptors, such as 5-HT3 A, neurokinin receptor 1(NK-1 R), and VIP receptor 1(VPAC1) in colon tissues was investigated by Western blot. The binding affinity of the brain-gut peptide receptors to the main components of HLHPD was analyzed by molecular docking. After HLHPD intervention, UC mice showed increased body weight, reduced DAI score and occult blood, prolonged colon, down-regulated levels of TNF-α, IL-1ß, and IL-6 in colon tissues, and relieved pathological damage in the colon. The VIP levels in the colon were significantly up-regulated in the HLHPD groups. The high-and medium-dose HLHPD could significantly down-regulated SP and 5-HT in colon tissues and 5-HT in the serum, and up-regulated the VIP in the serum. The high-dose HLHPD group could down-regulate 5-HT and up-regulate VIP in the hypothalamus. It is suggested that HLHPD can reverse the levels of brain-gut peptides in UC mice to varying degrees. Correlation analysis results suggested that the expression levels of brain-gut peptides in the hypothalamus, serum, and colon tissues were related to inflammatory factors. Molecular docking results showed that berberine, coptisine, and epiberberine were presumedly the material basis for HLHPD in regulating the levels of 5-HT3 A, NK-1 R, and VPAC1. The main components of HLHPD may reduce colonic inflammation and pathological damage of colon tissues by regulating the activity of brain-gut peptides and their receptors, thereby reducing DSS-induced colitis in mice.


Subject(s)
Colitis, Ulcerative , Animals , Brain-Gut Axis , Colitis, Ulcerative/drug therapy , Colon , Disease Models, Animal , Drugs, Chinese Herbal , Interleukin-6/metabolism , Male , Mice , Mice, Inbred C57BL , Molecular Docking Simulation , Serotonin/metabolism , Tumor Necrosis Factor-alpha/metabolism
6.
Inorg Chem ; 60(9): 6550-6558, 2021 May 03.
Article in English | MEDLINE | ID: mdl-33861587

ABSTRACT

A versatile microporous metal-organic framework (MOF), {[Cu(TIA)]·1.5CH3OH}n (Cu-1), was successfully obtained via the solvothermal reaction of cuprous(II) salt with the bifunctional ligand 3-(1H-1,2,4-triazol-1-yl)isophthalic acid. Single-crystal X-ray diffraction studies indicate that Cu-1 contains an apo three-dimensional skeleton and two types of one-dimensional channels. The framework of Cu-1 has excellent acid-alkali resistance and thermal stability, which is stable in a pH = 2-13 aqueous solution and an 260 °C air environment. In addition, the microporous copper MOF shows very high uptakes of CO2 (180 cm3·g-1) and C2H2 (113 cm3·g-1) at 273 K and displays excellent adsorption selectivity for small molecular gases. The ideal adsorbed solution theory selectivity values for C2H2/C2H4, CO2/CH4, and CO2/N2 are 2, 9, and 22 at 298 K, respectively. At the same time, breakthrough experiments for CO2/CH4, CO2/N2, and C2H2/C2H4 were further conducted to verify the efficient separation performances.

7.
Nanotechnology ; 32(4): 045710, 2021 Jan 22.
Article in English | MEDLINE | ID: mdl-33045697

ABSTRACT

Three isostructural pillared-layer frameworks with M-BDC-X layers supported by ditopic HL connectors, [M(HL)(BDC)0.5X] n (HL = 4'-(4-hydroxyphenyl)-4,2':6',4″-terpyridine, BDC = terephthalate, M = Cd, X = Cl for (1), M = Cd, X = formate for (2), and M = Co, X = formate for (3)), were solvothermally synthesized, and used as photocatalysts for Pt-assisted visible-light-initiated hydrogen evolution from water splitting. These water-durable frameworks exhibit varied hydrogen production rates of 361.2, 271.3, and 327.5 µmol · g-1 · h-1 in 12 h due to their slightly different donor environments of the octahedral CdII and CoII ions. Further experimental and theoretical investigations reveal that the metal ions and the local coordination surroundings have essentially dominated the conduction band minimum and electric resistance of the charge transport, which play highly important roles for the improved catalytic hydrogen evolution ability. These findings demonstrate the electronic effect of the slightly ligand field modifications on the boosting hydrogen generation activity in the noble metal-assisted MOF photocatalytic systems.

8.
Phys Chem Chem Phys ; 23(2): 1443-1453, 2021 Jan 21.
Article in English | MEDLINE | ID: mdl-33398308

ABSTRACT

The exploration of innovative molecular switches has resulted in large developments in the field of molecular electronics. Focusing on a single molecular switch with different forms exhibiting different electride features, potassium-atom-doped all-cis 1,2,3,4,5,6-hexafluorocyclohexane K-F6C6H6 was studied theoretically. It was found that an oriented external electric field can drive excess electron transfer from the region outside of the K atom to that outside of F6C6H6. Subsequently, the electride-like molecule K-F6C6H6 (1) switches into the molecular electride K-F6C6H6e- (3) through another electride-like molecule K-F6C6H6 (2). The static first hyperpolarizabilities (ß0) are increased over 12- and 5-fold when moving from 1 to 2 and 3, respectively. The rise of each ß0 value constitutes an order of magnitude improvement. Between them, the different ß0 values suggest that K-F6C6H6 is a good candidate for use as a multiple-response nonlinear optics switch. The order of the ß0 values of 1-4 for M-F6C6H6 (M = Li and Na) coincide with that of K-F6C6H6, also exhibiting a switch effect.

9.
Ophthalmic Res ; 64(1): 85-90, 2021.
Article in English | MEDLINE | ID: mdl-32305980

ABSTRACT

OBJECTIVE: To evaluate the effect of constant C for ray tracing-assisted intraocular lens (IOL) power calculation in patients with different refractive power, we compared the refractive outcome of the ray tracing method based on constant C and conventional IOL calculation. METHODS: 215 eyes which underwent phacoemulsification and IOL implantation were enrolled in the study. According to the average corneal power, patients were divided into 3 groups: high corneal power (K >45 D) group, medium corneal power (43 ≤ K ≤ 45 D) group, and low corneal power (K <43 D) group. The predicted sphero-equivalent refractive outcome for the IOL power implanted at surgery was calculated using the ray tracing method, SRK/T, and Haigis formulas. RESULTS: On the basis of the corneal refractive power, there were 65 eyes of K >45 D (30.23%), 96 eyes of 43 ≤ K ≤ 45 D (44.65%), and 54 eyes of K <43 D (25.12%). In general, the ray tracing group had the smallest value of mean absolute error (MAE) and mean error, and the proportions of eyes with absolute error (AE) <0.50 and <0.75 D were significantly higher than those of the other 2 formulas (p = 0.010). In each group, the value of MAE was smallest in the ray tracing group; for the proportions of AEs <0.50 and <0.75 D, the values in the ray tracing group were higher than those in the SRK/T and Haigis groups. Especially in the high and low corneal refractive groups, the proportion of AE <0.25 D was also obviously higher, but only in the low corneal refractive power group, and the difference was statistically significant (p = 0.006). CONCLUSIONS: Compared with the conventional formulas, C constant of the ray tracing-assisted IOL power calculation has more accuracy for the patients with different corneal refractive powers. Ray tracing could provide better guidance for IOL selection clinically.


Subject(s)
Cornea/pathology , Lens Implantation, Intraocular/methods , Lenses, Intraocular , Optics and Photonics , Refraction, Ocular/physiology , Visual Acuity , Biometry , Corneal Topography/methods , Follow-Up Studies , Humans , Postoperative Period , Retrospective Studies
10.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 43(3): 452-461, 2021 Jun 30.
Article in Zh | MEDLINE | ID: mdl-34238423

ABSTRACT

The primary and secondary tuberculosis features two completely different pathogenesis.At present,the pathogenesis of primary tuberculosis has been clear,whereas that of secondary tuberculosis remains unclear.In order to decipher the mechanism of secondary infection of Mycobacterium tuberculosis and provide insights into vaccine research and drug development,this paper reviews the problems of the widely accepted mechanism of secondary infection,the new findings of the research on the mechanism,as well as the role of cord factors.


Subject(s)
Coinfection , Mycobacterium tuberculosis , Tuberculosis, Pulmonary , Tuberculosis , Cord Factors , Humans
11.
Zhongguo Zhong Yao Za Zhi ; 46(1): 33-40, 2021 Jan.
Article in Zh | MEDLINE | ID: mdl-33645048

ABSTRACT

Berberine is the main extract of Coptis chinensis, and its anti-inflammatory, antioxidant, antibacterial and immunomodulatory effects have been confirmed by modern studies. Ulcerative colitis(UC) is a chronic, idiopathic inflammatory bowel disease with unknown etiology. Its causes involve genetics, intestinal microecology and mucosal immune system disorders. In this paper, literatures on relevant pathways and mechanism of berberine on ulcerative colitis in recent years were consulted and summarized to provide me-thods and ideas for developing berberine in the treatment of UC and exploring the mechanisms. The results showed that berberine protects the intestinal mucosal barrier, restores the body's normal immune response, and improves oxidative stress by regulating multiple signaling pathways, such as JAK-STAT, NK-κB, PI3 K-AKT, MAPK, Nrf2, ERS, and MLCK-MLC, so as to treat UC.


Subject(s)
Berberine , Colitis, Ulcerative , Colitis , Berberine/pharmacology , Colitis, Ulcerative/drug therapy , Colitis, Ulcerative/genetics , Humans , Intestinal Mucosa , Signal Transduction
12.
J Synchrotron Radiat ; 23(Pt 4): 937-46, 2016 07.
Article in English | MEDLINE | ID: mdl-27359142

ABSTRACT

This study investigates the distributions of Br, Ca, Cl, Cr, Cu, K, Fe, Mn, Pb, Ti, V and Zn in Phragmites australis root system and the function of Fe nanoparticles in scavenging metals in the root epidermis using synchrotron X-ray microfluorescence, synchrotron transmission X-ray microscope measurement and synchrotron X-ray absorption near-edge structure techniques. The purpose of this study is to understand the mobility of metals in wetland plant root systems after their uptake from rhizosphere soils. Phragmites australis samples were collected in the Yangtze River intertidal zone in July 2013. The results indicate that Fe nanoparticles are present in the root epidermis and that other metals correlate significantly with Fe, suggesting that Fe nanoparticles play an important role in metal scavenging in the epidermis.

13.
J Phys Chem A ; 119(10): 2083-90, 2015 Mar 12.
Article in English | MEDLINE | ID: mdl-25695357

ABSTRACT

Modulation of intermolecular interactions in response to external electric fields could be fundamental to the formation of unusual forms of water, such as water whiskers. However, a detailed understanding of the nature of intermolecular interactions in such systems is lacking. In this paper, we present novel theoretical results based on electron correlation calculations regarding the nature of H-bonds in water whiskers, which is revealed by studying their evolution under external electric fields with various field strengths. We find that the water whiskers consisting of 2-7 water molecules all have a chain-length dependent critical electric field. Under the critical electric field, the most compact chain structures are obtained, featuring very strong H-bonds, herein referred to as covalent H-bonds. In the case of a water dimer whisker, the bond length of the novel covalent H-bond shortens by 25%, the covalent bond order increases by 9 times, and accordingly the H-bond energy is strengthened by 5 times compared to the normal H-bond in a (H2O)2 cluster. Below the critical electric field, it is observed that, with increasing field strength, H-bonding orbitals display gradual evolutions in the orbital energy, orbital ordering, and orbital nature (i.e., from typical π-style orbital to unusual σ-style double H-bonding orbital). We also show that, beyond the critical electric field, a single water whisker may disintegrate to form a loosely bound zwitterionic chain due to a relay-style proton transfer, whereas two water whiskers may undergo intermolecular cross-linking to form a quasi-two-dimensional water network. Overall, these results help shed new insight on the effects of electric fields on water whisker formation.

14.
Int J Mol Sci ; 16(8): 19886-919, 2015 Aug 21.
Article in English | MEDLINE | ID: mdl-26307974

ABSTRACT

Non-coding RNAs (ncRNAs) have recently gained attention because of their involvement in different biological processes. An increasing number of studies have demonstrated that mutations or abnormal expression of ncRNAs are closely associated with various diseases including cancer. The present review is a comprehensive examination of the aberrant regulation of ncRNAs in colorectal cancer (CRC) and a summary of the current findings on ncRNAs, including long ncRNAs, microRNAs, small interfering RNAs, small nucleolar RNAs, small nuclear RNAs, Piwi-interacting RNAs, and circular RNAs. These ncRNAs might become novel biomarkers and targets as well as potential therapeutic tools for the treatment of CRC in the near future and this review may provide important clues for further research on CRC and for the selection of effective therapeutic targets.


Subject(s)
Biomarkers, Tumor/genetics , Colorectal Neoplasms/genetics , RNA, Untranslated/genetics , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Biomarkers, Tumor/antagonists & inhibitors , Biomarkers, Tumor/metabolism , Colorectal Neoplasms/drug therapy , Gene Expression Regulation, Neoplastic/drug effects , Humans , Mutation , RNA, Untranslated/antagonists & inhibitors , RNA, Untranslated/classification
15.
Int J Ophthalmol ; 17(2): 348-352, 2024.
Article in English | MEDLINE | ID: mdl-38371254

ABSTRACT

AIM: To investigate the efficacy of a new visual acuity (VA) screening method, the baby vision test for young children. METHODS: A total 105 eyes of 65 children aged 2-8y were included in the study. Acuity testing was conducted using a standardized recognition acuity chart (Snellen visual chart: at 3 m) and the baby vision model assessment. The baby vision device includes a screen, a near infrared camera and a computer. Children were seated at a measured distance of 33-40 cm from a display for testing. VA was estimated according to the highest resolution the children could follow. Decimal VA data were converted to logarithm of the minimum angle of resolution (logMAR) for statistical analysis. The VA results for each child were recorded and analyzed for consistency. RESULTS: The mean VA measured using the Snellen visual chart was 0.62±0.32, and that assessed using the baby vision test was 0.66±0.27. The 95% limit of agreement was -0.609 to 0.695, with 95.2% (100/105) plots within the 95% limits of agreement. VA values of the baby vision test were significantly correlated with those of the Snellen chart (R=0.274, P=0.005). CONCLUSION: The baby vision test can be used as a relatively reliable method for estimating VA in young children. This new acuity assessment might be a valid predictor of optotype-measured acuity later in preverbal children.

16.
ACS Macro Lett ; 13(1): 52-57, 2024 01 16.
Article in English | MEDLINE | ID: mdl-38147539

ABSTRACT

The development of single-component materials with low cytotoxicity and multichannel fluorescence imaging capability is a research hotspot. In the present work, highly electron-deficient pyrazine monomers were covalently connected into a polyurethane backbone using addition polymerization with terminal poly(ethylene glycol) monomethyl ether units containing a high density of electron pairs. Thereby, an amphiphilic polyurethane-pyrazine (PUP) derivative has been synthesized. The polymer displays cluster-induced emission through compact inter- and/or intramolecular noncovalent interactions and extensive through-space electron coupling and delocalization. Molecular rigidity facilitates red-shifted emission. Based on hydrophilic/hydrophobic interactions and excitation dependence emission at low concentrations, PUP has been self-assembled into fluorescent nanoparticles (PUP NPs) without additional surfactant. PUP NPs have been used for cellular multicolor imaging to provide a variety of switchable colors on demand. This work provides a simple molecular design for environmentally sustainable, luminescent materials with excellent photophysical properties, biocompatibility, low cytotoxicity, and color modulation.


Subject(s)
Polyethylene Glycols , Polyurethanes , Polyethylene Glycols/chemistry , Polymers/chemistry , Pyrazines
17.
Ecol Evol ; 14(5): e11445, 2024 May.
Article in English | MEDLINE | ID: mdl-38779528

ABSTRACT

Habitat is fundamental for facilitating various life activities in animals, for instance, snakes procure essential energy for survival and reproduction by selecting ambush microhabitats. While there has been extensive research on the selection of microhabitat for feeding in terrestrial and aquatic snakes, little is known about arboreal snakes. In the present study, we analyzed the ambush microhabitat preferences of Viridovipera stejnegeri, a widely distributed Asian pitviper in China, conducted association analysis between snake microhabitat and prey microhabitat and abundance to determine the ro5le of microhabitat selection in feeding. Employing random forest analysis and habitat selection functions, we further constructed a predictive framework for assessing the probability of ambush site selection by V. stejnegeri. Our results revealed that V. stejnegeri exhibited a distinct microhabitat preference for ambush prey. Among the 13 environmental factors assessed, V. stejnegeri showed pronounced preferences towards 12 of these factors, including climatic factors, geographical factors, and vegetation factors. Furthermore, although the preferences of V. stejnegeri overlapped substantially with those of its prey across multiple habitat factors, food abundance shows no significant association with various habitat factors of V. stejnegeri, and does not have significant predictive effect on habitat selection of V. stejnegeri. Therefore, we infer that V. stejnegeri does not preferentially select microhabitats with the highest food abundance, which does not support the hypothesis that "snakes select habitats based on the spatial distribution of prey abundance." By analyzing the characteristics of vegetation, geography, and climate, we conclude that V. stejnegeri tends to choose microhabitats with better ambush conditions to increase attack success rate, thereby achieving the optimal feeding success rate at the microhabitat scale, which is in line with the predictions of optimal foraging theory. This study provides new insights into the predation ecology and habitat selection of snakes.

18.
Analyst ; 138(16): 4483-92, 2013 Aug 21.
Article in English | MEDLINE | ID: mdl-23778299

ABSTRACT

Backgrounds existing in the analytical signal always impair the effectiveness of signals and compromise selectivity and sensitivity of analytical methods. In order to perform further qualitative or quantitative analysis, the background should be corrected with a reasonable method. For this purpose, a new automatic method for background correction, which is based on morphological operations and weighted penalized least squares (MPLS), has been developed in this paper. It requires neither prior knowledge about the background nor an iteration procedure or manual selection of a suitable local minimum value. The method has been successfully applied to simulated datasets as well as experimental datasets from different instruments. The results show that the method is quite flexible and could handle different kinds of backgrounds. The proposed MPLS method is implemented and available as an open source package at http://code.google.com/p/mpls.


Subject(s)
Algorithms , Least-Squares Analysis , Spectrum Analysis, Raman/methods , Smoke/analysis , Nicotiana/chemistry
19.
J Phys Chem A ; 117(30): 6678-86, 2013 Aug 01.
Article in English | MEDLINE | ID: mdl-23819837

ABSTRACT

Interesting effects of the cage unit size and number of cage units as well as bridge unit on the static first hyperpolarizabilities (ß0) for novel multicage electrides are revealed. (1) The small cage unit C8 systems have larger ß0 for cage unit size effect. (2) The ß0 increases with increasing cage unit number. (3) The effect of the bridge between cage units on ß0 is O > NH > CH2. Specially, a novel relationship between the excess electron cloud and ß0 is revealed. Assembling the three effects, the constructed multicage electride structure with three small C8 cage units connected by the O-bridge (K···3C8(O)) is a electride salt K(+)[e@3C8(O)](-) and has the considerable ß0 value of 7.1 × 10(5) au, which is about 55 times larger than the 13 000 au of the single-cage electride molecule Na3O(+)(e@C20F20)(-). The novel multicage strategy is effective to enhance nonlinear optical (NLO) response.

20.
J Phys Chem A ; 117(13): 2835-43, 2013 Apr 04.
Article in English | MEDLINE | ID: mdl-23488897

ABSTRACT

Using the strong electron hole cage C20F19 acceptor, the NH2...M/M3O (M = Li, Na, and K) complicated donors with excess electron, and the unusual σ chain (CH2)4 bridge, we construct a new kind of electride molecular salt e(-)@C20F19-(CH2)4-NH2...M(+)/M3O(+) (M = Li, Na, and K) with excess electron anion inside the hole cage (to be encapsulated excess electron-hole pair) serving as a new A-B-D strategy for enhancing nonlinear optical (NLO) response. An interesting push-pull mechanism of excess electron generation and its long-range transfer is exhibited. The excess electron is pushed out from the (super)alkali atom M/M3O by the lone pair of NH2 in the donor and further pulled inside the hole cage C20F19 acceptor through the efficient long σ chain (CH2)4 bridge. Owing to the long-range electron transfer, the new designed electride molecular salts with the excess electron-hole pair exhibit large NLO response. For the e(-)@C20F19-(CH2)4-NH2...Na(+), its large first hyperpolarizability (ß0) reaches up to 9.5 × 10(6) au, which is about 2.4 × 10(4) times the 400 au for the relative e(-)@C20F20...Na(+) without the extended chain (CH2)4-NH2. It is shown that the new strategy is considerably efficient in enhancing the NLO response for the salts. In addition, the effects of different bridges and alkali atomic number on ß0 are also exhibited. Further, three modulating factors are found for enhancing NLO response. They are the σ chain bridge, bridge-end group with lone pair, and (super)alkali atom. The new knowledge may be significant for designing new NLO materials and electronic devices with electrons inside the cages. They may also be the basis of establishing potential organic chemistry with electron-hole pair.

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