Controllable Self-Assembly of SERS Hotspots in Liquid Environment

Controllable synthesis of novel metal nanoparticles and effective capture of hotspots are of great significance for SERS (surface-enhanced Raman spectroscopy) detection. Therefore, in this paper, a green controllable synthesis method of gold nanoparticle was achieved via epigallocatechin gallate reduction. Different morphologies of gold nanoparticles were synthesized just by changing the solution pH values, and the growth kinetics of AuNPs (gold nanoparticles) were systematically studied. The synthetic AuNPs were put in a droplet to study dynamic variations of self-assembly SERS hotspots from the liquid sol state to the solid dry state. The addition of halogen ions in the droplet can controllably regulate the self-assembly three-dimensional hotspot model of gold nanoparticles in the evaporation process of a droplet, during which the most enhancement effect can be easily captured. The dynamically changing images of nanoparticles in the process were graphically described based on the internal interaction forces of a droplet. Two stronger areas in the changes of SERS intensity were achieved with a high concentration of halogen ions, while only one maximum intensity area was obtained with a low concentration of halogen ions added. This method can effectively avoid complex and unpredictable microenvironments of SERS substrates in the liquid drop, further improving the reproducibility of SERS detection as well as broadening it to biological applications.

Combined Fracture of Carpal and Volar Divergent Dislocation of the Second to Fifth Carpometacarpal Joints

The volar divergent dislocation of the second to fifth carpometacarpal joints and involving fracture of carpal is an extremely rare injury. We reported a case of 55-year-old man, victim of a motorbike, who was struck by a car, admitted at the emergency department unable to move his left hand with severe swelling. X-rays and CT scan showed a volar divergent dislocation of second to fifth carpometacarpal joints and involving fracture of carpal. Patient underwent closed reduction and plaster fixation right way, after one week, he received open reduction internal fixation with K-wire and plaster. Functional exercise was started progressively once K-wire and plaster were removed after six weeks. At six months follow-up, results were excellent and patient has regained all of his range of motion and hand activities. Key words: carpometacarpal joint, palmar, divergent, dislocation, hand, wrist.

Revealing the Magnesium-Storage Mechanism in Mesoporous Bismuth via Spectroscopy and Ab-Initio Simulations

We present mesoporous bismuth nanosheets as a model to study the charge-storage mechanism of Mg/Bi systems in magnesium-ion batteries (MIBs). Using a systematic spectroscopy investigation of combined synchrotron-based operando X-ray diffraction, near-edge X-ray absorption fine structure and Raman, we demonstrate a reversible two-step alloying reaction mechanism Bi↔MgBi↔Mg₃ Bi₂ . Ab-initio simulation methods disclose the formation of a MgBi intermediate and confirm its high electronic conductivity. This intermediate serves as a buffer for the significant volume expansion (204 %) and acts to regulate Mg storage kinetics. The mesoporous bismuth nanosheets, as an ideal material for the investigation of the Mg charge-storage mechanism, effectively alleviate volume expansion and enable significant electrochemical performance in a lithium-free electrolyte. These findings will benefit mechanistic understandings and advance material designs for MIBs.

A novel method based on convolutional neural network for malaria diagnosis

Malaria is one of the three major diseases with the highest mortality worldwide and can turn fatal if not taken seriously. The key to surviving this disease is its early diagnosis. However, manual diagnosis is time consuming and tedious due to the large amount of image data. Generally, computer-aided diagnosis can effectively improve doctors’ perception and accuracy. This paper presents a medical diagnosis method powered by convolutional neural network (CNN) to extract features from images and improve early detection of malaria. The image sharpening and histogram equalization method are used aiming at enlarging the difference between parasitized regions and other area. Dropout technology is employed in every convolutional layer to reduce overfitting in the network, which is proved to be effective. The proposed CNN model achieves a significant performance with the best classification accuracy of 99.98%. Moreover, this paper compares the proposed model with the pretrained CNNs and other traditional algorithms. The results indicate the proposed model can achieve state-of-the-art performance from multiple metrics. In general, the novelty of this work is the reduction of the CNN structure to only five layers, thereby greatly reducing the running time and the number of parameters, which is demonstrated in the experiments. Furthermore, the proposed model can assist clinicians to accurately diagnose the malaria disease.

Synergistic enhancement effect of MoO3@Ag hybrid nanostructures for boosting selective detection sensitivity

An ex situ method was used to synthesize noble metals and metal oxide composite materials, due to the selective adsorption properties of metal oxides, the adsorption of different probe molecules by this composite structure had been studied. In the ex situ approach, we use (3-aminopropyl) diethoxy methylsilane (ATES) as a coupling agent which is easy for noble metal nanoparticles deposited on metallic oxide nanomaterials. The Raman scattering (SERS) substrate of 1D MoO₃ nanowires (MoO₃-NWs) @Ag nanoparticles (Ag-NPs) hybrid surface had been fabricated. Several parameters are presented in the following which influences the morphology of self-assembly and SERS activity: (i) coupling agent of ATES, (ii) ATES content (iii) Ag-NPs content. The finite difference time domain (FDTD) method is to explain the enhancement mechanism distribution of the hybrid substrate. Different probe molecules (R6G, Methylene Blue, Crystal Violet, and 4-ATP) have been adsorbed for SERS tests. Improved principle component analysis (PCA) is adopted to obtain the minimum detection limit of probe molecules. Through the DFT calculation, different absorption strengths between the target molecules and the MoO₃(010) surface have been illustrated, which is also the main reason for the selective enhancement effect of MoO₃@Ag hybrid nanostructures. This paper might propose a method to prepare such enhancement substrate based on the selective absorption properties of oxide semiconductors.

[Significance of celiac branch of the vagal nerve in function-preserving gastrectomy]

Function-preserving gastrectomy, especially pylorus-preserving gastrectomy (PPG), can improve the quality of life and has been widely recognized. With the development of surgical techniques and equipment, nerve preservation has become a new requirement in the era of "precision medicine", but the preservation of celiac branch of the vagal nerve remains controversial in gastric cancer surgery. Current researches have shown that the preservation of celiac branch of the vagal nerve is safe and feasible in patients with early gastric cancer. Although controversial, nerve preservation may play a role in preventing gallstones, regulating gastric emptying, reducing dumping syndrome, alleviating chronic diarrhea, reducing gastroesophageal reflux, and inhibiting bile reflux. The significance of the celiac branch of the vagal nerve in gastric cancer surgery is worth further attention and exploration to promote the development of function-preserving gastrectomy and improve the quality of life of patients.

Identification of 1-phenyl-4-cyano-5-aminopyrazoles as novel ecdysone receptor ligands by virtual screening, structural optimization, and biological evaluations

Ecdysteroids initiate the molting process in insects by binding to the ecdysone receptor (EcR), which is a promising target for identifying insect growth regulators. This paper presents an in silico/in vitro screening procedure for identifying new EcR ligands. The three-step virtual screening procedure uses a three-dimensional pharmacophore model, docking and Molecular Mechanics/Poisson-Boltzmann Surface Area (MM/PBSA) rescoring routine. A novel hit (VS14) with good binding activity against Plutella xylostella EcR was identified from a library of over 200,000 chemicals. Subsequently, the 1-phenyl-4-cyano-5-aminopyrazole scaffold and twelve EcR ligands were synthesized. Their IC₅₀ values against Plutella xylostella EcR ranged from 0.64 to 23.21 μm. Furthermore, a preliminary analysis of the structure-activity relationship for novel scaffolds provided a basis for designing new ligands with improved activity.

[The value of spectral CT-based radiomics in preoperative prediction of lymph node metastasis of advanced gastric cancer]

Objective: To investigate the spectral CT-based radiomics in predicting preoperatively the lymph node metastasis (LNM) of advanced gastric cancer. Methods: From January 2014 to October 2018, the spectral CT imaging and clinical data of 196 gastric adenocarcinoma patients confirmed by pathology in the First Affiliated Hospital of Zhengzhou University were retrospectively enrolled (training set and test set were randomly divided according to the ratio of 1∶1). These 196 patients include143 males and 53 females, aged from 28 to 81 years, with an average age of (59±11) years, and were divided into nodular metastasis group and non-metastasis group according to clinicopathological data. The spectral parameters were measured and calculated, and the CT-reported lymph node (LN) status from CT images were obtained. 273 radiomics features were extracted from the dual-phases CT images in different energy level (40, 65 and 100 keV) to build the radiomics signature respectively. Univariate analysis was used to compare the differences of spectral parameters and radiomics features between two groups, and then the significant indicators were put into multivariable logistic regression analysis to construct combined prediction model and radiomics nomogram. In addition, the performance of prediction model in training and test set were measured using the receiver operating characteristics (ROC) curves and were compared using DeLong test. Results: Both in training set and in test set, the iodine concentration (IC) of tumor in venous phase (VP) in nodular metastasis group were higher than that in non-metastasis group [training set: 22.98 (100 mg/L)>20.31 (100 mg/L), P=0.086; test set: 25.14 (100 mg/L)>21.07 (100 mg/L), P=0.009]. The CT-reported LN status showed significant differences between the two group (P<0.001, P=0.001). The radiomics signatures 40 keV-arterial phase, 65 keV-venous phase, IC-VP of tumor and CT-reported LN status were independent indicators for prediction of preoperative LNM of advanced gastric cancer in combined prediction model (P<0.05). The radiomics nomogram predicated LNM with an area under curve (AUC) and 95% confidence interval (CI) of 0.822 (0.739-0.906) in training set and 0.819(0.732-0.906) in test set, and there were no significant differences in AUC between two sets (P>0.05). Conclusions: The spectral CT-based radiomics can be used to quantitatively predict the LNM of advanced gastric cancer preoperatively.

Mechanism of Cross-modal Information Influencing Taste

Studies on the integration of cross-modal information with taste perception has been mostly limited to uni-modal level. The cross-modal sensory interaction and the neural network of information processing and its control were not fully explored and the mechanisms remain poorly understood. This mini review investigated the impact of uni-modal and multi-modal information on the taste perception, from the perspective of cognitive status, such as emotion, expectation and attention, and discussed the hypothesis that the cognitive status is the key step for visual sense to exert influence on taste. This work may help researchers better understand the mechanism of cross-modal information processing and further develop neutrally-based artificial intelligent (AI) system.

Cellular Redox-Related Transcription Factor Nrf2 Mediation of HaTrf Response to Host Plant Allelochemical 2-Tridecanone in Helicoverpa armigera

Despite there being a number of excellent studies on detoxification enzyme-mediated interaction between insect and plant allelochemical, there are no reports on the pathway of the transferrin effect in insect response to host plant allelochemical. Our research indicates that Helicoverpa armigera transferrin (HaTrf) inhibited the apoptotic cell death treated by 2-tridecanone, a host plant allelochemical present in tomato species (Lycopersicon hirsutum f. glabratum), by cellular redox-related transcription factor nuclear factor erythroid-2-related factor 2 (Nrf2). Nrf2 can defend organisms against the detrimental effects of oxidative stress and play pivotal roles in preventing host plant allelochemical-related toxicity. This study explains how HaTrf inhibited the apoptotic cell death during exposure to host plant allelochemical 2-tridecanone and provides a novel view on transferrin and its anti-apoptotic role in plant-insect interactions.

FRI0031 OBSERVATIONS ON BIOMARKERS IN VERY EARLY RHEUMATOID ARTHRITIS CONSECUTIVELY RECRUITED OVER 20 YEARS, FROM BASELINE PRESENTATION TO FIVE-YEAR OUTCOMES

Background:

Since July 1998, the Early Undifferentiated PolyArthritis (EUPA) cohort recruited consecutive adults with recent-onset immune-mediated polyarthritis1,2. Patients were treated aiming at 0 swollen joint.

Objectives:

To analyze the impact of biomarkers over 20 years on baseline variables, treatments, comorbidities and outcomes over the first 5 years of follow up.

Methods:

Variables and Outcomes were collected over 5 years in consecutive patients fulfilling RA criteria, grouped according to date of inclusion (Period 1: 1998-2004; Period 2: 2005-2010; Period 3: 2011-2018). Comparisons of baseline characteristics, treatment, and outcomes over 5 years between the 3 Periods were previously presented (ACR 2018 and 2019). Erosive damage was scored according to Sharp/van der Heijde; erosive status was defined as ≥5 Erosion units. We now present observed associations between the presence of baseline prognostic biomarkers (anti-CCP2 (ACPA), RF, anti-Sa, and erosive status) with concomitant and subsequent disease activity levels, radiographic scores, comorbidities and impact of treatment. False discovery rate correction was used to adjust p-values for multiple comparisons.

Results:

753 patients were included: 247, 263 and 243 in Periods 1, 2 and 3, respectively. Variables at baseline. No biomarkers, including erosive status, were associated with demographics or disease activity. Erosive disease was more prevalent in ACPA+ (19.9% vs 13.9%, p=0.0417). Current smoking decreased by period (20.6, 17.2, 8.6%; p=0.02) in ACPA negatives only, remaining stable among ACPA+ (25.3, 20.9, 18.8%, NS). All comorbidities were significantly more present in ACPA negatives vs positives (RR between 1.55 and 1.99). Prevalence of cardiovascular (CV; 44.8, 55.0, 60.0%; p=0.036) and cancer (4.1, 7.1, 13.1%; p=0.02) comorbidities increased over time in ACPA negatives and remained stable in ACPA+ (CV: 33.0, 30.8, 40.7, NS; cancer: 3.0, 4.4, 6.2, NS). RF positivity decreased by period (47.8, 36.9, 36.7%, p=0.03), but ACPA+ remained stable (40.8, 35, 35.4% NS).

Outcomes over 5 years of follow up.

There was no link between the presence of any biomarker and subsequent disease activity scores. Positive ACPA, RF and anti-Sa at baseline predicted development of more erosive status (RR = 1.50; 1.37 and 1.52, all p<0.001). 68% reached DAS28 remission overall (70.3% in ACPA negatives, 65.2% in ACPA+). Independent of ACPA status, remission rates increased between Periods 1 vs 2 (RR = 1.14, p=0.04) and 1 vs 3 (RR=1.13, p=0.055), but not between 2 vs 3. CV comorbidities among ACPA+ increased significantly more over time vs ACPA negatives (+8.9% vs +4.1%; RR = 1.18, p=0.03). Erosion scores increased significantly more in ACPA+ treated with DMARDs only vs receiving a biologic (ΔSharp: 3.98 vs 3.11, p= 0.026; ΔErosions: 2.58 vs 1.83, p= 0.02). By period, erosive status decreased significantly (Periods 2 vs 1: RR= 0.65, p=0.002; 3 vs 1: RR=0.42, p=0.002; 3 vs 2: RR=0.64, p=0.007), both in ACPA+ and negatives.

Conclusion:

In this cohort of recent onset RA recruited over 20 years, we observed a constant drift towards RF-negative arthritis at baseline with decreasing smoking rates and increasing comorbidities in seronegative patients. Positive antibodies were associated more cardiovascular comorbidities accrual. Autoantibody positive (especially ACPA+) patients developed more erosive disease and had better erosion outcomes with biologic treatments. Irrespective of the presence or absence of biomarkers, marked improvements in control of disease activity and in remission rates occured over each period.

References:

[1]Boire G, et al.Arthritis Res Ther2005;7:R592-R603;

[2]Carrier N, et al. Arthritis Res Ther2016;18:37

Disclosure of Interests:

Nathalie Carrier: None declared, Sophie Roux: None declared, Ariel Masetto: None declared, Artur J. deBrum Fernandes: None declared, Patrick Liang: None declared, Meryem Maoui Employee of: Bristol Myers Squibb Canada, Gilles Boire Grant/research support from: Merck Canada (Registry of biologices, Improvement of comorbidity surveillance)

Amgen Canada (CATCH, clinical nurse)

Abbvie (CATCH, clinical nurse)

Pfizer (CATCH, Registry of biologics, Clinical nurse)

Hoffman-LaRoche (CATCH)

UCB Canada (CATCH, Clinical nurse)

BMS (CATCH, Clinical nurse, Observational Study Protocol IM101664. SEROPOSITIVITY IN A LARGE CANADIAN OBSERVATIONAL COHORT)

Janssen (CATCH)

Celgene (Clinical nurse)

Eli Lilly (Registry of biologics, Clinical nurse), Consultant of: Eli Lilly, Janssen, Novartis, Pfizer, Speakers bureau: Merck, BMS, Pfizer

Recommendation of Antimicrobial Dosing Optimization During Continuous Renal Replacement Therapy

Continuous Renal Replacement Therapy (CRRT) is more and more widely used in patients for various indications recent years. It is still intricate for clinicians to decide a suitable empiric antimicrobial dosing for patients receiving CRRT. Inappropriate doses of antimicrobial agents may lead to treatment failure or drug resistance of pathogens. CRRT factors, patient individual conditions and drug pharmacokinetics/pharmacodynamics are the main elements effecting the antimicrobial dosing adjustment. With the development of CRRT techniques, some antimicrobial dosing recommendations in earlier studies were no longer appropriate for clinical use now. Here, we reviewed the literatures involving in new progresses of antimicrobial dosages, and complied the updated empirical dosing strategies based on CRRT modalities and effluent flow rates. The following antimicrobial agents were included for review: flucloxacillin, piperacillin/tazobactam, ceftriaxone, ceftazidime/avibactam, cefepime, ceftolozane/tazobactam, sulbactam, meropenem, imipenem, panipenem, biapenem, ertapenem, doripenem, amikacin, ciprofloxacin, levofloxacin, moxifloxacin, clindamycin, azithromycin, tigecycline, polymyxin B, colistin, vancomycin, teicoplanin, linezolid, daptomycin, sulfamethoxazole/trimethoprim, fluconazole, voriconazole, posaconzole, caspofungin, micafungin, amphotericin B, acyclovir, ganciclovir, oseltamivir, and peramivir.

A balsam pear-shaped CuO SERS substrate with highly chemical enhancement for pesticide residue detection

Simple and traditional hydrothermal fabrication of a novel balsam pear-shaped CuO with high SERS enhancement is presented. XRD (X-ray diffraction), SEM (scanning electronic microscopy), TEM (transmission electron microscope), HRTEM (high-resolution transmission electron microscope), UV-Vis, and Raman are adopted to ensure that this balsam pear-shaped CuO with dense nanoparticle protuberance is successfully prepared. The LOD of this CuO SERS substrate is 4.79 μg L^-1 with R6G as molecular probe. By using DFT (density functional theory) calculation and FDTD (finite difference time domainmethod) simulation, both EM (electromagnetic enhancement) and CM (chemical enhancement) mechanisms are investigated, and the results show that these two-enhancement mechanisms can coexist in this balsam pear-shaped CuO. Finally, the prepared substrate has been applied for the determination of trace levels of paraquat in solution , and results show that its LOD for paraquat is 275 μg L^-1 (optimum Raman band: 1646 cm^-1 Raman shift), which is better than the government standard in China. A dexterous and facile way for fabrication of CuO SERS-active substrates with low cost and high performance, quite promising in detection of chemically hazardous substances and pesticide residue is provided. Graphical abstract.

Amino acids serve as an important energy source for adult flukes of Clonorchis sinensis

Clonorchiasis, caused by chronic infection with Clonorchis sinensis (C. sinensis), is an important food-borne parasitic disease that seriously afflicts more than 35 million people globally, resulting in a socioeconomic burden in endemic regions. C. sinensis adults long-term inhabit the microaerobic and limited-glucose environment of the bile ducts. Energy metabolism plays a key role in facilitating the adaptation of adult flukes to crowded habitat and hostile environment. To understand energy source for adult flukes, we compared the component and content of free amino acids between C. sinensis-infected and uninfected bile. The results showed that the concentrations of free amino acids, including aspartic acid, serine, glycine, alanine, histidine, asparagine, threonine, lysine, hydroxylysine, and urea, were significantly higher in C. sinensis-infected bile than those in uninfected bile. Furthermore, exogenous amino acids could be utilized by adult flukes via the gluconeogenesis pathway regardless of the absence or presence of exogenous glucose, and the rate-limiting enzymes, such as C. sinensis glucose-6-phosphatase, fructose-1,6-bisphosphatase, phosphoenolpyruvate carboxykinase, and pyruvate carboxylase, exhibited high expression levels by quantitative real-time PCR analysis. Interestingly, no matter whether exogenous glucose was present, inhibition of gluconeogenesis reduced the glucose and glycogen levels as well as the viability and survival time of adult flukes. These results suggest that gluconeogenesis might play a vital role in energy metabolism of C. sinensis and exogenous amino acids probably serve as an important energy source that benefits the continued survival of adult flukes in the host. Our study will be a cornerstone for illuminating the biological characteristics of C. sinensis and the host-parasite interactions.

Clonorchiasis, closely related to cholangiocarcinoma and hepatocellular carcinoma, has led to a negative socioeconomic impact in global areas especially some Asian endemic regions. Owing to the emergence of drug resistance and hypersensitivity reactions after the massive and repeated use of praziquantel as well as the lack of effective vaccines, searching for new strategies that prevent and treat clonorchiasis has become an urgent matter. Clonorchis sinensis, the causative agent of clonorchiasis, long-term inhabits the microaerobic and limited-glucose environment of the bile ducts. Adequate nutrients are essential for adult flukes to resist the adverse condition and survive in the crowed habitat. Studies on energy metabolism of adult flukes are beneficial for further exploring host-parasite interactions and developing novel anti-parasitic drugs. Our results suggest that gluconeogenesis probably plays a vital role in energy metabolism of Clonorchis sinensis and exogenous amino acids might be an essential energy source for adult flukes to successfully survive in the host. Our foundational study opens a new avenue for explaining energy metabolism of Clonorchis sinensis and provides a valuable strategy that the gluconeogenesis pathway will be a potential and novel target for the prevention and treatment of clonorchiasis.

Role of Host GPR120 in Mediating Dietary Omega-3 Fatty Acid Inhibition of Prostate Cancer

Background

GPR120, a G protein-coupled receptor for long-chain polyunsaturated fatty acids (FAs), mediates the anti-inflammatory effects of omega-3 (ω-3) FAs. We investigated whether host or tumor GPR120 plays a role in the anti-prostate cancer effects of ω-3 FAs.

Methods

MycCap prostate cancer allografts were grown in immunocompetent wild-type (WT) and GPR120 knockout (KO) mice fed ω-3 (fish oil) or ω-6 (corn oil) diets. Immune cell infiltration was quantified by flow cytometry, and gene expression of immune cell markers in isolated tumor-associated macrophages (TAMs) was quantified by quantitative real-time polymerase chain reaction. Archived tissue from a fish oil intervention trial was used to correlate gene expression of GPR120 with cell cycle progression (CCP) genes and Ki67 index (n = 11-15 per group). All statistical tests were two-sided.

Results

In WT mice (n = 7 per group), dietary ω-3 FAs decreased MycCap allograft tumor growth (mean [SD] final tumor volume ω-6 = 491 [437] mm3 vs ω-3 = 127 [77] mm3, P = .04), whereas in global GPR120KO mice (n = 7 per group) ω-3 FAs had no anticancer effects. Dietary ω-3 FAs inhibited GPR120KO-MycCaP allografts grown in WT mice (n = 8 per group; mean [SD] final tumor volume ω-6 = 776 [767] mm3 vs ω-3 = 36 [34] mm3, P = .02). Omega-3 FA treatment decreased the number of M2-like TAMs in tumor tissue and gene expression of M2 markers in isolated TAMs compared with ω-6 controls in WT (n = 7 per group) but not in GPR120KO mice (n = 7 per group). In human tissue, higher expression of stromal GPR120 correlated with greater reduction in expression of CCP genes in men with prostate cancer on a high-ω-3 diet (r = -.57, P = .04).

Conclusions

Host GPR120 plays a central role in the anti-prostate cancer effects of dietary ω-3 FAs. Future studies are required to determine if the anticancer effects of ω-3 FAs are mediated through inhibition of M2-like macrophages and if host GPR120 status predicts anticancer effects of dietary ω-3 FAs in men with prostate cancer.

A facile seed growth method to prepare stable Ag@ZrO2 core-shell SERS substrate with high stability in extreme environments

A stable substrate is extraordinarily important for the trace detection of Surface Enhanced Raman Scattering technique. We have designed in this paper a simple seed growth method to prepare Ag@ZrO₂ core-shell nanoparticles as well as regulate the core-shell ratio by adjusted concentration of zirconium propoxides added. The shell thickness effect and spacing on SERS activities have been simulated in different finite time domains, which goes perfectly with those previous experiment results. With Ag@ZrO₂ core-shell nanoparticles adopted as the SERS substrate and R6G as molecular probe, the detection range could reach as great as 10^-8 M. The regression model, obtained through principal component analysis, is adopted for some rapid and precise detection; and the determination coefficient (R²) is going up to 0.9743, proving that the SERS substrate we have prepared has extremely high detection accuracy. To explore the stability of core-shell nanoparticles, we have taken both two different cases of strong acid solution as well as strong alkali solution for the core-shell nanoparticle etching, and this is how a SERS test could be carried out. These experimental results have indicated that the outer zirconia layer could keep the silver surface from oxidation and its stability is ensured, quite crucial for the applied SERS.

Discovery of an Aedes (Stegomyia) albopictus population and first records of Aedes (Stegomyia) aegypti in Canada

A population of Aedes (Stegomyia) albopictus (Skuse) (Diptera: Culicidae), a vector of chikungunya, dengue, yellow fever, and Zika and West Nile viruses, has been detected in Windsor, Ontario, Canada from 2016 onwards. Here, we describe its seasonal distribution, as well as the various aquatic habitats from which this species was collected and its larval co-habitation. We collected immatures from tires, treeholes, extruded polystyrene foam containers, discarded plastic cups, old recycling bins and oviposition traps. Aedes albopictus larvae were collected with Aedes japonicus (Theobald), Anopheles punctipennis (Say), Culex pipiens Linnaeus, Ochlerotatus hendersoni (Cockerell), Ochlerotatus triseriatus (Say) and Orthopodomyia signifera (Coquillett). Adult female and male specimens were collected from Biogents sentinel traps (Biogents AG, Regensburg, Germany), as well as Centers for Disease Control and Prevention miniature light traps (CDC, Atlanta, GA, U.S.A.), and also as they alighted on the investigators. Peak adult collections occurred in September during epidemiological week 37. We also collected Aedes (Stegomyia) aegypti (Linnaeus), a new record for Canada, in 2016 and from two new collection sites in 2017. The 2017 collections were 3.5 km north and 19.4 km south of the index site. The present study adds to the increasing number of studies reporting range expansions of these mosquito species.

Defect Passivation and Photoluminescence Enhancement of Monolayer MoS2 Crystals through Sodium Halide-Assisted Chemical Vapor Deposition Growth

Recent success in the chemical vapor deposition (CVD) growth of atomically thin transition metal dichalcogenide (TMD) crystals opens up prospects for exploiting these materials in nanoelectronic and optoelectronic devices. However, CVD-grown TMDs often suffer from weak crystal quality because of the formation of defects during the growth, which makes a large impact on their electrical and optical properties. Here, we report a facile synthesis of high-quality MoS₂ monolayers through a sodium halide-assisted CVD method. Our results show that the addition of sodium halides into MoO₃ precursors leads to the rapid growth of highly crystalline MoS₂ monolayers. Moreover, the overall photoluminescence (PL) intensity of MoS₂ monolayers can be greatly enhanced by up to 2 orders of magnitude. The PL enhancement originates from that the deep trap states induced by sulfur vacancies are passivated by the substitution doping of halogen atoms, which promotes the emission of excitons and trions. Density functional theory calculations indicate that the band gaps of halogen-doped MoS₂ monolayers are slightly smaller than those of pristine MoS₂ monolayer, which is responsible for the small red shift of PL peaks (∼30 meV). These findings provide a new route toward engineering electronic and optical properties of MoS₂ and other TMD monolayers.

A Review of Chinese Raman Spectroscopy Research Over the Past Twenty Years

This paper introduces the major Chinese research groups in the fields of biomedicine, food safety, environmental testing, material research, archaeological and cultural relics, gem identification, forensic science, and other research areas of Raman spectroscopy and combined methods spanning the two decades from 1997 to 2017. Briefly summarized are the research directions and contents of the major Chinese Raman spectroscopy research groups, giving researchers engaged in Raman spectroscopy research a more comprehensive understanding of the state of Chinese Raman spectroscopy research and future development trends to further develop Raman spectroscopy and its applications.