H酸单钠盐在石墨与闪锌矿浮选分离中的选择性抑制机理

采用纯矿物浮选实验、傅里叶变换红外光谱(FT-IR)测试、Zeta电位测试、X射线光电子能谱(XPS)分析和分子动力学模拟研究H酸单钠盐(HAMS)存在下石墨和闪锌矿的浮选行为和分离、抑制机理。在最佳浮选条件下,混合浮选精矿中闪锌矿和石墨的回收率分别为93.37%和4.98%。Zeta电位测试和XPS分析表明,HAMS大量吸附在石墨表面,而在闪锌矿表面几乎不吸附。FT-IR测试表明,HAMS在石墨表面没有明显的化学吸附。分子动力学模拟结果表明,HAMS中的萘环与石墨之间的疏水相互作用是导致HAMS吸附在石墨表面的主要原因。

Transepithelial photorefractive keratectomy mode using SCHWIND-ESIRIS excimer laser:initial clinical results

AIM: To evaluate postoperative pain, uncorrected visual acuity (UCVA), and cornea haze value after transepithelial photorefractive keratectomy (T-PRK) performed with aspherical ablation profile using SCHWIND ESIRIS excimer laser. METHODS: Retrospective case series. Fifty-nine eyes (32 patients) with myopia associated with or without astigmatism underwent phototherapeutic keratectomy (PTK) followed by photorefractive keratectomy (PRK) which performed by Optimized Refractive Keratecomy (ORK)-CAM software based on aspherical ablation profile using SCHWIND ESIRIS excimer laser. Postoperative pain scale was measured on a questionnaire through five levels. Haze was graded by five grades, and UCVA, manifest refraction spherical equivalent (MRSE) were analyzed. RESULTS: Mean pain level was (1.37 +/- 0.613) (range: 1 to 3), the mean time picking out the soft contact lens was (6.22 +/- 1.73) days, at 3 months, UCVA was 1.0 for 40 eyes (67.8%), 0.5 for all eyes (100.0%). The UCVA was significantly less than the preoperative best spectacle corrected visual acuity (BSCVA) (t=-2.84, P=0.006), haze value was (0.27 +/- 0.25), no patients had a haze grade up to 2. Mean MRSE was (0.76 +/- 0.96) diopter(D) by 3 months. CONCLUSION: The outcomes from this study show that using the SCHWIND ESIRIS aspherical ablation profile for transepithelial PRK has a good visual result. The primary advantage is related to a spherical ablation profile, automatically considers the ablation volume of the stroma and the accurate and smooth removal of the epithelium with PTK. Additional studies are needed to determine long-term outcomes.

An inversion decomposition method for better energy resolution of NaI(Tl)scintillation detectors based on a Gaussian response matrix

NaI(T1) scintillation detectors have been widely applied for gamma-ray spectrum measurements owing to advantages such as high detection efficiency and low price.However,the mitigation of the limited energy resolution of these detectors,which detracts from an accurate analysis of the instrument spectra obtained,remains a crucial need.Based on the physical properties and spectrum formation processes of NaI(T1) scintillation detectors,the detector response to gamma photons with different energies is represented by photopeaks that are approximately Gaussian in shape with unique full-width-at-half-maximum(FWHM) values.The FWHM is established as a detector parameter based on resolution calibrations and is used in the construction of a general Gaussian response matrix,which is employed for the inverse decomposition of gamma spectra obtained from the detector.The Gold and Boosted Gold iterative algorithms are employed to accelerate the decomposition of the measured spectrum.Tests of the inverse decomposition method on multiple simulated overlapping peaks and on experimentally obtained U and Th radionuclide series spectra verify the practicability of the method,particularly in the low-energy region of the spectrum,providing for the accurate qualitative and quantitative analysis of radionuclides.

An inversion decomposition test based on Monte Carlo response matrix on the γ-ray spectra from NaI(Tl) scintillation detector

The Na I(Tl) scintillation detector has a number of unique advantages, including wide use, high light yield,and its low price. It is difficult to obtain the decomposition of instrument response spectrum because of limitations associated with the Na I(Tl) scintillation detector's energy resolution. This paper, based on the physical process of c photons released from decay nuclides, generating an instrument response spectrum, uses the Monte Carlo method to simulate c photons with Na I(Tl) scintillation detector interaction. The Monte Carlo response matrix is established by different single energy γ-rays with detector effects. The Gold and the improved Boosted-Gold iterative algorithms have also been used in this paper to solve the response matrix parameters through decomposing tests,such as simulating a multi-characteristic energy c-ray spectrum and simulating synthesized overlapping peaks cray spectrum. An inversion decomposition of the c instrument response spectrum for measured samples(U series, Th series and U–Th mixed sources, among others)can be achieved under the response matrix. The decomposing spectrum can be better distinguished between the similar energy characteristic peaks, which improve the error levels of activity analysis caused by the overlapping peak with significant effects.

Neuroprotective effects of gypenosides in experimental autoimmune optic neuritis

AIM：To determine whether gypenosides have protective effects in experimental autoimmune optic neuritis（EAON）.METHODS：Mice were randomly divided into seven groups：control group,model group,three different density gypenosides monotherapy,methylprednisolone monotherapy,combination of gypenosides and methylprednisolone group.The control group was subcutaneously injected with oil emulsion adjuvant and all other groups were subcutaneously immunized with an emulsified mixture of myelin oligodendrocyte glycoprotein（MOG） 35-55 peptide to induce EAON.Mice in the gypenosides groups were administered injections daily with three concentrations（15 mg/kg,30 mg/kg,45 mg/kg） of gypenosides respectively.Mice in the methylprednisolone group and the combination treatment group were injected daily with methylprednisolone（20 mg/kg） or methylprednisolone（20 mg/kg） ＋ gypenosides（30 mg/kg）,respectively.After MOG immunization,visual evoked potential（VEP）,optical coherence tomography（OCT）,and histopathologic examination were performed at 14,20,30,and 40 d post-inoculation（p.i.）.All results were expressed as mean±SEM.The data were evaluated by oneway ANOVA followed by Tukey or Games-Howell test.RESULTS：Compared with the control group,p2 latency was prolonged in the model group（P=0.041）.Combination treatment can alleviated the change in VEP at 20 d p.i.（P=0.012）.Average peripapillary retinal nerve fiber layer（RNFL） thickness was reduced in the model group（P= 0.000,30d;P=0.000,40d） and gypenosides treatment remarkably diminished the degree of RNFL degenerationat 30 d and 40 d p.i（P=0.000,30d;P=0.000,40d）.The pathomorphological results showed a decrease in demyelination（P=0.020） and inflammatory reactions in the combination group compared with the model group（20d p.i.）.Gypenosides treatment also alleviated the degree of axonal loss（40d p.i.）（P=0.003）.CONCLUSION：Treatment with gypenosides exerts protective effects on retinal nerve fibers and axons in EAON.When combined with gypenosides,methylprednisolone reduces demyelination in the acute stage of EAON.

Design of Gamma Spectrum Data Acquisition and Processing System Based on ARM / DSP

Research for detecting or obtaining radionuclide by gamma energy spectrum data acquisition and process system is one of the key issues about intelligent measurement of gamma-ray spectrum. For this reason, a software and hardware implementation schematic design based on ARM ( Advanced RISC Machines) + DSP ( Digital Signal Processor) architecture for gamma energy spectrum data acquisition and processing system is proposed. The paper discusses in detail some key technologies such as communication interface design between microcontroller ARM and digital signal processor DSP,distribution scheduling under multi-task in the ARM-Linux,DSP handling procedures for multi-channel A / D high-speed sample. At the same time,because the traditional Gaussian fitting to determine the boundary of peak is not ideal,it puts forward a weighting factor of Gaussian function least squares fitting realize boundary determined. Finally gamma-spectrum data from sodium iodide NaI( TI) scintillation detector is tested and processed in the new system. The results show that gamma energy spectrum data acquisition and process system is perfect functionality, stable and convergence in unimodal. Compared with data from conventional energy spectrometers,the system can keep better energy resolution in a wide range of pulse pass rate.

Application of topological soliton in modeling protein folding: Recent progress and perspective

Proteins are important biological molecules whose structures are closely related to their specific functions. Understanding how the protein folds under physical principles, known as the protein folding problem, is one of the main tasks in modern biophysics. Coarse-grained methods play an increasingly important role in the simulation of protein folding, especially for large proteins. In recent years, we proposed a novel coarse-grained method derived from the topological soliton model, in terms of the backbone Cα chain. In this review, we will first systematically address the theoretical method of topological soliton. Then some successful applications will be displayed, including the thermodynamics simulation of protein folding, the property analysis of dynamic conformations, and the multi-scale simulation scheme. Finally, we will give a perspective on the development and application of topological soliton.

Research on Comparison and Evaluation Studies of Several Smoothing Denoising Method Based on γ-ray Spectrum Detector

The extraction of spectral parameters is very difficult because of the limited energy resolution for NaI （TI） gamma-ray detectors. For statistical fluctuation of radioactivity under complex environment, some smoothing filtering methods are proposed to solve the problem. These methods include adopting method of arithmetic moving average, center of gravity, least squares of polynomial, slide converter of discrete funcion convolution etc. The process of spectrum data is realized, and the results are assessed in H/FWHM（ Peak High/Full Width at Half Maximum） and peak area based on the Matlab programming. The results indicate that different methods smoothed spectrum have respective superiority in different ergoregion, but the Gaussian function theory in discrete function convolution slide method is used to filter the complex y-spectrum on Embedded system nlatform, and the statistical fluctuation of y-snectrum filtered wall.

8-iso-prostaglandin-F2α:a possible trigger or accelerator of diabetic retinopathy

INTRODUCTIONDiabetes mellitus （DM） is a global disease, the number of patients of which is predicted to rise to about 380 million by 2025 by the World Health Organization （WHO）. Diabetic retinopathy （DR） is one of the most sigificant complications in DM and the first cause of irreversible blindness of adults in the world It occurs in 90% of patients after 20-30y from the diagnosis of DM, and about 5 million individuals have DR, which is responsible for approximately 5% of blindness worldwide.

Epstein-Barr virus-encoded small RNAs in idiopathic orbital inflammatory pseudotumor tissues: a comparative case series

AIM： To investigate the positive rate and types of cells that express Epstein-Barr virus-encoded small RNAs （EBERs） and to determine the distribution of EBER-expressing cells in idiopathic orbital inflammatory pseudotumor （IOIP） tissues. METHODS： We retrospectively examined 40 archived paraffin specimens from two teaching hospitals in Southern China between January 2007 and January 2015 that were pathologically determined to exhibit IOIP. Eleven concurrent paraffin specimens of thyroid-associated ophthalmopathy （TAO） composed the control group. In situ hybridization was performed to detect EBERs. Immunohistochemistry was employed to detect CD3, CD20, Vimentin, and smooth muscle actin （SMA）, and the positive rate, types of positive cells, and distribution and location of EBERs were evaluated. RESULTS： The positive expression rate of EBERs was 47.5% （19/40） in the IOIP group, which was significantly higher than that in the TAO group [0 （0/11）, P=-0.011]. in the IOIP group, the lymphocyte infiltrative subtype, fibrotic subtype, and mixed subtype exhibited EBER-positive rates of 57.1% （12121）, 12.5% （118）, and 54.5% （6/11）, respectively, and no significant differences were found between these subtypes （P=0.085）. Positive signals of EBERs were mainly present in medium-small lymphocytes between or around follicles and in the nuclei of activated immunoblasts （14/19）. CONCLUSION： The positive rate, types, and distribution of EBER-expressing cells in IOIP have been documented.These findings are conducive for a better understanding of the underlying mechanisms of Epstein-Barr virus infection in IOIP pathogenesis.

Trismus originating from rare fungal myositis in pterygoid muscles:A case report

BACKGROUND Trismus is a common problem with various causes.Any abnormal conditions of relevant anatomic structures that disturb the free movement of the jaw might provoke trismus.Trismus has a detrimental effect on the quality of life.The outcome of this abnormality is critically dependent on timely diagnosis and treatment,and it is difficult to identify the true origin in some cases.We present a rare case of trismus due to fungal myositis in the pterygoid muscle,excluding any other possible pathogenesis.CASE SUMMARY The patient presented with a 2-mo history of restricted mouth opening.Computed tomography showed obvious enlargement of the left pterygoid muscles.Furthermore,the patient had trismus without obvious predisposing causes.The primary diagnosis was pterygoid myosarcoma.Consequently,lesionectomy of the left pterygoid muscle was performed.Intraoperative frozen biopsy implied the possibility of an uncommon infection.Postoperative pathologic examination confirmed myositis and necrosis in the pterygoid muscle.Fungi were detected in both muscle tissue and surrounding necrotic tissue.The patient recovered well with antifungal therapy and mouth opening exercises.The rarity of fungal myositis may be responsible for the misdiagnosis.Although the origin of pathogenic fungi is still unknown,we believe that both hematogenous spread and local invasion could be the most likely sources.To the best of our knowledge,this is the
rst case in the literature that reported fungal myositis in pterygoid muscles as the only reason that results in trismus.CONCLUSION Surgeons should remain vigilant to the possibility of trismus originating from fungal myositis.

Clinical differences between young and older patients with optic neuritis

Background:To compare clinical features in young(18-44 years)and older patients(>44 years)with optic neuritis(ON).Methods:This is a retrospective case series study.One hundred thirty-three young cases and 51 older cases diagnosed with ON were reviewed.Results:The older patients had lower proportion of disc swelling(37.3%vs.57.1%,P=0.016),but higher proportion of brain plaques(21.6%vs.7.5%,P=0.007)compared with the young patients.The proportion of patients suffered from hypertension or hyperglycemia was nearly 6 times higher in the older patients than in the young patients(29.4%vs.5.3%,P<0.001).There were no significant differences in other clinical parameters[including gender,eye pain,clinical evidence of multiple sclerosis and best corrected visual acuity(BCVA)]between the older and young patients.Conclusions:There are some distinct differences between young patients(18-44 years)and older patients(>44 years).Physicians should pay attention to the side effects of corticosteroids in elderly patients in clinical practice,although they are generally safe.

Characterizing a large outbreak of dengue fever in Guangdong Province, China

Background:Dengue cases have been reported each year for the past 25 years in Guangdong Province,China with a recorded historical peak in 2014.This study aims to describe the epidemiological characteristics of this large outbreak in order to better understand its epidemic factors and to inform control strategies.Methods:Data for clinically diagnosed and laboratory-confirmed dengue fever cases in 2014 were extracted from the China Notifiable Infectious Disease Reporting System.We analyzed the incidence and characteristics of imported and indigenous cases in terms of population,temporal and spatial distributions.Results:A total of 45224 dengue fever cases and 6 deaths were notified in Guangdong Province in 2014,with an incidence of 47.3 per 100000 people.The elderly(65+years)represented 11.7%of total indigenous cases with the highest incidence(72.3 per 100000).Household workers and the unemployed accounted for 23.1%of indigenous cases.The majority of indigenous cases occurred in the 37th to 44th week of 2014(September and October)and almost all(20 of 21)prefecture-level cities in Guangdong were affected.Compared to the non-Pearl River Delta Region,the Pearl River Delta Region accounted for the majority of dengue cases and reported cases earlier in 2014.Dengue virus serotypes 1(DENV-1),2(DENV-2)and 3(DENV-3)were detected and DENV-1 was predominant(88.4%).Conclusions:Dengue fever is a serious public health problem and is emerging as a continuous threat in Guangdong Province.There is an urgent need to enhance dengue surveillance and control,especially for the high-risk populations in high-risk areas.

Recent Progress in Symplectic Algorithms for Use in Quantum Systems

In this paper we survey recent progress in symplectic algorithms for use in quantum systems in the following topics:Symplectic schemes for solving Hamiltonian systems;Classical trajectories of diatomic systems,model molecule A2B,Hydrogen ion H+2 and elementary atmospheric reaction N(4S)+O2(X 3Σ−g)→NO(X 2Π)+O(3P)calculated by means of Runge-Kutta methods and symplectic methods;the classical dissociation of the HF molecule and classical dynamics of H+2 in an intense laser field;the symplectic form and symplectic-scheme shooting method for the time-independent Schr¨odinger equation;the computation of continuum eigenfunction of the Schr¨odinger equation;asymptotic boundary conditions for solving the time-dependent Schr¨odinger equation of an atom in an intense laser field;symplectic discretization based on asymptotic boundary condition and the numerical eigenfunction expansion;and applications in computing multi-photon ionization,above-threshold ionization,Rabbi oscillation and high-order harmonic generation of laser-atom interaction.

Immunogenicity and safety of a recombinant fusion protein vaccine(V-01)against coronavirus disease 2019 in healthy adults:a randomized,double-blind,placebo-controlled,phaseⅡtrial

Background:Innovative coronavirus disease 2019(COVID-19)vaccines,with elevated global manufacturing capacity,enhanced safety and efficacy,simplified dosing regimens,and distribution that is less cold chain-dependent,are still global imperatives for tackling the ongoing pandemic.A previous phase I trial indicated that the recombinant COVID-19 vaccine(V-01),which contains a fusion protein(IFN-PADRE-RBD-Fc dimer)as its antigen,is safe and well tolerated,capable of inducing rapid and robust immune responses,and warranted further testing in additional clinical trials.Herein,we aimed to assess the immunogenicity and safety of V-01,providing rationales of appropriate dose regimen for further efficacy study.Methods:A randomized,double-blind,placebo-controlled phaseⅡclinical trial was initiated at the Gaozhou Municipal Centre for Disease Control and Prevention(Guangdong,China)in March 2021.Both younger(n=440;18–59 years of age)and older(n=440;≥60 years of age)adult participants in this trial were sequentially recruited into two distinct groups:two-dose regimen group in which participants were randomized either to follow a 10 or 25 mg of V-01 or placebo given intramuscularly 21 days apart(allocation ratio,3:3:1,n=120,120,40 for each regimen,respectively),or one-dose regimen groups in which participants were randomized either to receive a single injection of 50 mg of V-01 or placebo(allocation ratio,3:1,n=120,40,respectively).The primary immunogenicity endpoints were the geometric mean titers of neutralizing antibodies against live severe acute respiratory syndrome coronavirus 2,and specific binding antibodies to the receptor binding domain(RBD).The primary safety endpoint evaluation was the frequencies and percentages of overall adverse events(AEs)within 30 days after full immunization.Results:V-01 provoked substantial immune responses in the two-dose group,achieving encouragingly high titers of neutralizing antibody and anti-RBDimmunoglobulin,which peaked at day 35(161.9[95%confidence interval[CI]:133.3–196.7]and 149.3[95%CI:123.9–179.9]in 10 and 25 mg V-01 group of younger adults,respectively;111.6[95%CI:89.6–139.1]and 111.1[95%CI:89.2–138.4]in 10 and 25 mg V-01 group of older adults,respectively),and remained high at day 49 after a day-21 second dose;these levels significantly exceed those in convalescent serum from symptomatic COVID-19 patients(53.6,95%CI:31.3–91.7).Our preliminary data showthat V-01 is safe andwell tolerated,with reactogenicity predominantly being absent or mild in severity and only one vaccinerelated grade 3 or worse AE being observed within 30 days.The older adult participants demonstrated a more favorable safety profile compared with those in the younger adult group:with AEs percentages of 19.2%,25.8%,17.5%in older adults vs.34.2%,23.3%,26.7%in younger adults at the 10,25 mg V-01 two-dose group,and 50 mg V-01 one-dose group,respectively.Conclusions:The vaccine candidate V-01 appears to be safe and immunogenic.The preliminary findings support the advancement of the two-dose,10 mg V-01 regimen to a phaseⅢtrial for a large-scale population-based evaluation of safety and efficacy.