Superimposed Hermite-Gaussian-correlated Schell-model beam with multiple off-axis vortices.

We first introduce a class of a superimposed Hermite-Gaussian-correlated Schell model with a multiple off-axis vortices beam, with the side lobe of the beam carrying one to four vortex singularities at the source plane. Subsequently, the variation laws of this beam after being focused by a thin lens are studied theoretically to obtain the optimal beam parameters. The numerical simulation results show that the beam possesses a unique multiple vortex structure, phase structure, and orbital angular momentum. Its intensity resembles a spiral staircase rotating around the axes. The rotational symmetry property of the transverse energy flow along the z axis was broken by the vortices. The hot spot position can be adjusted flexibly by changing the off-axis distance of vortices. This study is of great significance for nondestructive capture and manipulation of multiple particles or cells.

Shaping the focal intensity distribution using a partially coherent radially polarized beam with multiple off-axis vortices.

A new kind of partially coherent vector vortex beam, namely, the partially coherent radially polarized (PCRP) beam with multiple off-axis vortices, is introduced, and the average intensity distributions of such vortex beam focused by a thin lens are investigated theoretically. It is novelty that the off-axis vortices will induce the focal intensity redistribution and reconstruction, while this remarkable characteristic will be vanished in the case of a very low coherence. In view of this distinctive feature, a new method has been put forward to shape or modulate the focal intensity distribution by elaborately tailoring the multiple off-axis vortices as well as the coherence length. More importantly, some peculiar focal fields with novel structures, such as bar-shaped, triangle-shaped, square-shaped, and pentagon-shaped hollow profiles or flat-top foci, are obtained. Our results indicate that modulating the multiple off-axis vortices provides an additional degree of freedom for focus shaping.

Evolution properties of the radially polarized Laguerre-Gaussian-correlated Schell-model beams propagating in uniaxial crystals.

In this paper, we discuss, both analytically and numerically, the paraxial propagation of the radially polarized Laguerre-Gaussian-correlated Schell-model (LGCSM) beams orthogonal to the optical axis in uniaxial crystals. The analytical expression for the cross-spectral density function and the second-order moments of the radially polarized LGCSM beams are derived, and the evolution properties of the normalized intensity distribution, the spectral degree of the coherence (SDOC), and the spectral degree of the polarization (SDOP) in uniaxial crystals are elucidated by numerical examples. It is found that the intensity distribution of the radially polarized LGCSM beams evolves from a doughnut shape into a solid shape and finally converts into an elliptical symmetric hollow-ring profile in uniaxial crystals due to the combined effect of special correlation functions and the anisotropy effect of the uniaxial crystals. The evolution of the SDOC and SDOP for the radially polarized LGCSM beams is quite different from that of the radially polarized Gaussian-Schell-model beams. In addition, the propagation properties of the radially polarized LGCSM beams are closely related to the spatial coherence length, the mode order, and the ratio of extraordinary and ordinary reflective indices. The results show that the uniaxial crystals could modulate the evolution properties of the radially polarized LGCSM beams.

Focus shaping of partially coherent radially polarized vortex beam with tunable topological charge.

In this paper, we have introduced a new class of partially coherent vector vortex beams, named radially polarized multi-Gaussian Schell-model (MGSM) vortex beam, carrying the vortex phase with tunable topological charges (i.e., both integral and fractional values) as a natural extension of the radially polarized MGSM beam. The tight focusing properties of the radially polarized MGSM vortex beam passing through a high numerical aperture (NA) objective lens are investigated numerically based on the vectorial diffraction theory. Numerical results show that the focal intensity distributions of the radially polarized MGSM vortex beam can be shaped by regulating the structure of the correlation functions and the topological charge of vortex phase. In contrast with the integral vortex beam, the most intriguing property of the fractional vortex beam is that the focal intensity distribution at the focal plane can be nonuniformity and asymmetry, while such unique characteristics will vanish when the spatial coherence length is sufficiently small. Furthermore, some focal fields with novel structure, such as a focal spot with nonuniform asymmetric or an anomalous asymmetric hollow focal field, can be formed by choosing suitable fractional values of topological charge and spatial coherence length. Our results will be useful for optical trapping, especially for trapping of irregular particles or manipulation of absorbing particles.

Propagation properties of partially coherent crescent-like beams under maritime environment.

Based on the extended Huygens-Fresnel principle, the analytical expressions for the intensity distribution, effective radius of curvature, beam wander, Strehl ratio, and the power in the bucket of a partially coherent crescent-like (PCCL) beam under the maritime environment are derived. The propagation properties of the PCCL beams through the maritime environment are investigated in detail. Numerical results indicate that, for the maritime environment, the propagation properties and beam quality of a PCCL beam are closely related to its initial beam parameters and the turbulence parameters. Comparative analyses are performed for the new models under the marine turbulence and the terrestrial turbulence. It turns out that the marine turbulence influences the beam width and the beam wander more than the terrestrial turbulence does. Also, the beam quality of the PCCL beams in marine turbulence can be improved by choosing a large beam width, high coherence length, or short wavelength. The PCCL beams have a range-dependent tilt, which can be useful for some practical applications, such as traveling around an obstacle. The results are of significance for over-the-sea communication systems.

Focus shaping of the radially polarized Laguerre-Gaussian-correlated Schell-model vortex beams.

In this paper, we introduce a new kind of partially coherent vector beam with special correlation function and vortex phase named radially polarized Laguerre-Gaussian-correlated Schell-model (LGCSM) vortex beam as a natural extension of scalar LGCSM vortex beam. The realizability conditions for such beam are derived. The tight focusing properties of a radially polarized LGCSM vortex beam passing through a high numerical aperture (NA) objective lens are investigated numerically based on the vectorial diffraction theory. We find that not only the transverse component but also the longitudinal component of the focal field distributions can be shaped by regulating the structures of the correlation functions, which is quite different from that of the conventional radially polarized partially coherent beam. Moreover, a series of wildly used focal field with novel structure, e.g., focal spot, flat-topped or doughnut beam profiles, needle-like focal field and controllable three-dimensional (3D) optical cage, were obtained. These results indicate that the focus shaping can be achieved by combining the regulation of the structures of the correlation functions with the regulation of beam parameters effectively. Our results may be useful for potential applications in optical trapping, optical high-resolution microscopy and optical data storage.

Evolution properties of the radially polarized multi-Gaussian Schell-model beam in uniaxial crystals.

The evolution properties of the normalized intensity distribution, the spectral degree of coherence (SDOC), and the spectral degree of polarization (SDOP) of the radially polarized multi-Gaussian Schell-model (MGSM) beam in uniaxial crystals are illustrated. Numerical results show that the intensity distribution of the radially polarized MGSM beam gradually evolves from a doughnut shape into an elliptical symmetric flattop shape and retains its elliptical flattop shape on further propagation in anisotropic crystals. The evolution behavior of the SDOC and SDOP for the radially polarized MGSM beam is quite different from that of the linearly polarized one. In addition, the influences of the spatial coherence length δ0, beam index M, and the ratio of the extraordinary refractive index to the ordinary refractive index ne/no of the uniaxial crystals on the evolution properties of the normalized intensity distribution, the SDOC, and the SDOP of the radially polarized MGSM beam are discussed in detail.

Position 22 of the V3 loop is associated with HIV infectivity.

Human immunodeficiency virus subtype 1B (HIV-1B) binds to the CD4 receptor and co-receptor CCR5 or CXCR4 to enter T lymphocytes. The amino acid sequence of the HIV envelope glycoprotein V3 region determines the co-receptor tropism, thereby influencing the infectivity of the virus. Our research group previously found that the amino acid at position 22 of the V3 region may affect the infectivity of the virus, and in this study, we tested this hypothesis. We constructed pseudoviruses by changing the amino acids at position 22 of the V3 region in CCR5-tropic and CXCR4-tropic viruses and tested their infectivity. When the amino acid at V3 position 22 was altered in the CCR5- and CXCR4-tropic viruses, their ability to infect cells decreased to 20.6% and 17.14%, respectively. Therefore, we propose that residue 22 in the V3 region of subtype HIV-1B significantly influences the infectivity of the virus.

Variation analysis of E1 and E2 in HCV subtypes.

Pegylated interferon and ribavirin combination therapy effectively suppresses viral replication in 50 %-60 % of hepatitis C virus (HCV)-infected patients. However, HCV-infected patients often display varied responses to therapy, and strains of subtype lb (the most widespread HCV subtype worldwide) have more-severe clinical manifestations, greater viral loads, and poorer responses to interferon treatment. Therefore, understanding the genomic variability of HCV is crucial to treatment of HCV infection. In this study, we used the appropriate software to analyze the nucleotide, and amino acid sequences of the envelope proteins (E1 and E2) of HCV to investigate the extent of their variability in several HCV subtypes (1a, 1b, 2a, 2b, 3a, 4a, 5a and 6a) and calculated the ratio of nonsynonymous to synonymous substitutions (dN/dS) in these proteins to investigate the immunological pressure acting on them. We also predicted the N-glycosylation sites in E1 and E2 to determine their association with viral neutralization. We found that E1 is more variable, has a higher dN/dS ratio, and has more N-glycosylation sites than E2 in HCV subtype 1b. This indicates that the variability of E1, its dN/dS ratio, and its degree of N-glycosylation might play an important role in the treatment of infection with HCV subtype 1b.

Propagation factors of cosine-Gaussian-correlated Schell-model beams in non-Kolmogorov turbulence.

Based on the extended Huygens-Fresnel principle and second-order moments of the Wigner distribution function (WDF), we have studied the relative root-mean-square (rms) angular width and the propagation factor of cosine-Gaussian-correlated Schell-model (CGSM) beams propagating in non-Kolmogorov turbulence. It has been found that the CGSM beam has advantage over the Gaussian Schell-model (GSM) beam for reducing the turbulence-induced degradation, and this advantage will be more obvious for the beams with larger parameter n and spatial coherence δ or under the condition of stronger fluctuation of turbulence. The CGSM beam with larger parameter n or smaller spatial coherence δ will be less affected by the turbulence. In addition, the effects of the slope-parameter α, inner and outer scale and the refractive-index structure constant of the non-Kolmogorov's power spectrum on the propagation factor are also analyzed in detailed.

Trends in HIV infection in the First Affiliated Hospital of Harbin, China.

BACKGROUND: Major hospitals in most Chinese cities have the capability to perform HIV testing. However, it is not a routine test for all patients and, as a result, many patients are not aware of their HIV status. To understand the rate of HIV infection and the factors associated with infection, we tested serum to determine HIV status and analyzed factors associated with HIV infection. METHODS: We collected blood samples from 348,151 patients who visited the First Affiliated Hospital of Harbin Medical University from 1 January 2007 to 31 December 2012. Serum was screened with an ELISA. If the test was positive, we conducted two additional ELISAs: a repeat with the initial kit and one with another kit. If there was a positive result with either of these two ELISA kits, western blotting was performed at Harbin Centers for Disease Control and Prevention. RESULTS: The HIV positivity rate of inpatients significantly increased during the course of this study. HIV infection in patients appeared to differ by sex, age, occupation, marital status, educational level, and route of infection. HIV was more prevalent in men than in women. More than 80% of HIV-positive patients had not received higher (>12 years) education. From 2007 to 2012, HIV-positive patients were mainly infected through sexual transmission. For sexually acquired infections, the rate of HIV infections through homosexual contact has increased rapidly in recent years, and ranged from 36.4% to 65.1%. CONCLUSIONS: The number of patients diagnosed as HIV positive has increased in recent years. Offering routine HIV testing in hospitals is feasible and can increase linkage to HIV care and treatment for many individuals.

CT and MR imaging features of soft tissue rhabdoid tumor: compared with rhabdomyosarcoma in children.

Objective: To assess the computed tomography (CT) and magnetic resonance (MR) imaging characteristics of soft tissue rhabdoid tumors (RT) and compare them with those of rhabdomyosarcoma (RMS). Methods: We conducted a retrospective analysis of 49 pediatric patients from 2011 to 2022, comprising 16 patients with soft tissue RT and 33 patients with RMS who underwent CT or MRI scans. Key imaging features, as well as clinical and pathological data, were compared between the two groups. The multivariate logistic regression analysis was used to determine independent differential factors for distinguishing soft tissue RT from RMS, and the model was established. The final prediction model was visualized by nomograms and verified internally by using a bootstrapped resample 1,000 times. The diagnostic accuracy of the combined model was assessed in terms of discrimination, calibration, and clinical utility. Results: Age, sex, number of lesions, and primary locations were similar in both groups. The imaging characteristics, including margin, calcification, surrounding blood vessels, and rim enhancement, were associated with the two groups of soft tissue tumors, as determined by univariate analysis (all p < 0.05). On multivariate logistic regression analysis, the presence of unclear margin (p-value, adjusted odds ratio [95% confidence interval]: 0.03, 7.96 [1.23, 51.67]) and calcification (0.012, 30.37 [2.09, 440.70]) were independent differential factors for predicting soft tissue RT over RMS. The presence of rim enhancement (0.007, 0.05 [0.01, 0.43]) was an independent differential factor for predicting RMS over soft tissue RT. The comprehensive model established by logistic regression analysis showed an AUC of 0.872 with 81.8% specificity and 81.3% sensitivity. The decision curve analysis (DCA) curve displayed that the model achieved a better net clinical benefit. Conclusion: Our study revealed that the image features of calcification, indistinct margins, and a lack of rim enhancement on CT and MRI might be reliable to distinguish soft tissue RT from RMS.

Complete genome sequence of Salmonella enterica serovar pullorum RKS5078.

Salmonella enterica serovar Pullorum is a chicken-adapted pathogen, causing pullorum disease. Its strict host adaptation has been suspected to result in gene decay. To validate this hypothesis and identify the decayed genes, we sequenced the complete genome of S. Pullorum RKS5078. We found 263 pseudogenes in this strain and conducted functional analyses of the decayed genes.

The genotype analysis of the hepatitis C virus in Heilongjiang Province, China.

ABSTRACT: Introduction: Hepatitis C virus (HCV) infection is a major public health issue. HCV genotype identification is clinically important to tailor the dosage and duration of treatment, and recombination in intra-patient populations of HCV may lead to the generation of escape mutants, as previously observed for other RNA viruses. Up to now, there is no study assessing HCV genotypes and subtypes in Heilongjiang Province, China.Methods: To determine genotype and phylogenetic analysis of HCV in Heilongjiang Province is crucial. In this study, we amplified 3 genome regions (5'UTR, E1, and NS5B) of 30 HCV patients in Heilongjiang Province, amplified products were analyzed by bioinformatics.Results: We found that 23 specimens had concordant subtypes in the 3 gene regions (2a and 1b), 7 HCV patients were considered the recombinants, the recombination pattern of the 7 HCV patients in the 5'UTR, E1, and NS5B region as followed: 1b/2a/1b, 2a/2a/1b, 1b/2a/2a, 1b/2a/1b, 1b/2a/1b, 1b/2a/1b, 2a/2a/1b.Conclusions: The findings in the present study showed that a higher recombination rate (23%) than other researches, and the recombination of 2a/1b in the 5'UTR, E1, and NS5B region was only found in the present study up to now.

Tunable multiband directional electromagnetic scattering from spoof Mie resonant structure.

We demonstrate that directional electromagnetic scattering can be realized in an artificial Mie resonant structure that supports electric and magnetic dipole modes simultaneously. The directivity of the far-field radiation pattern can be switched by changing wavelength of the incident light as well as tailoring the geometric parameters of the structure. In addition, we further design a quasiperiodic spoof Mie resonant structure by alternately inserting two materials into the slits. The results show that multi-band directional light scattering is realized by exciting multiple electric and magnetic dipole modes with different frequencies in the quasiperiodic structure. The presented design concept is suitable for microwave to terahertz region and can be applied to various advanced optical devices, such as antenna, metamaterial and metasurface.

Expression and location of Smad2, 4 mRNAs during and after liver fibrogenesis of rats.

AIM: To investigate the location alteration of Smad2 and Smad4 mRNAs in the liver during and after fibrogenesis in rats. METHODS: Eighty male Wistar rats weighing approximately 200 g each were used. The rat models of experimental hepatic fibrosis were established by injection with carbon tetrachloride (CCl4), normal rats and rats were injected with olive oil and served as control groups. In situ hybridization(ISH) was used to detect the Smad2 and Smad4 mRNA in liver. RESULTS: In situ hybridization showed Smad2 and Smad4 mRNA expressions in the cytoplasm of hepatic stellate cells (HSC), fibroblasts and myofibroblasts around the central vein and hepatic sinus during and after fibrogenesis. Expression of Smad2, 4 mRNA was higher than that in normal and control rats. CONCLUSION: In the process of and after hepatic fibrosis formation, HSC, fibroblasts and myofibroblasts are the major cells that express Smad2 and Smad4. The more serious the hepatic fibrosis is in the injured liver, the higher the level of Smad2 and Smad4 gene expression is during and after fibrogenesis respectively.

[Clinical study of multiple zonal aganglionosis in long segment Hirschsprung's disease].

OBJECTIVE: To discuss pathogeny and diagnosis and management of multiple zonal aganglionosis in Hirschsprung's disease. METHODS: Records of 3 children, aging 5 days, 29 days and 18 months, 3 boys, with multiple zonal aganglionosis in long segment Hirschsprung's disease between 1987-2005 were reviewed retrospectively. Total colectomy and Soave's operations were performed. RESULTS: 3 children were diagnosed HD before surgery, but the convulsive stenosis in distal ileum and proximal ascending colon were detected during surgery. The aganglionic cells in the stenosis gut were confirmed by pathologic diagnosis. CONCLUSIONS: The total colon and ileum should be detected carefully during surgery in children with long segment Hirschsprung's disease. It is believed not sound that the neuroblastic cells stop moving from neuroectoderm to gut in early gestation in HD, but it is also believed that some other causes in the course of gestation might interfere the normal growth of the ganglionic cells.

Value of dynamic ³¹P magnetic resonance spectroscopy technique in in vivo assessment of the skeletal muscle mitochondrial function in type 2 diabetes.

BACKGROUND: Phosphorous magnetic resonance spectroscopy ((31)P-MRS) has been successfully applied to study intracellular membrane compounds and high-energy phosphate metabolism. This study aimed to evaluate the capability of dynamic (31)P-MRS for assessing energy metabolism and mitochondrial function in skeletal muscle from type 2 diabetic patients. METHODS: Dynamic (31)P-MRS was performed on 22 patients with type 2 diabetes and 26 healthy volunteers. Spectra were acquired from quadriceps muscle while subjects were in a state of rest, at exercise and during recovery. The peak areas of inorganic phosphate (Pi), phosphocreatine (PCr), and adenosine triphosphate (ATP) were measured. The concentration of adenosine diphosphate (ADP) and the intracellular pH value were calculated from the biochemistry reaction equilibrium. The time constant and recovery rates of Pi, PCr, and ADP were analyzed using exponential curve fitting. RESULTS: As compared to healthy controls, type 2 diabetes patients had significantly lower skeletal muscle concentrations of Pi, PCr and ß-ATP, and higher levels of ADP and Pi/PCr. During exercise, diabetics experienced a significant Pi peak increase and PCr peak decrease, and once the exercise was completed both Pi and PCr peaks returned to resting levels. Quantitatively, the mean recovery rates of Pi and PCr in diabetes patients were (10.74 ± 1.26) mmol/s and (4.74 ± 2.36) mmol/s, respectively, which was significantly higher than in controls. CONCLUSIONS: Non-invasive quantitative (31)P-MRS is able to detect energy metabolism inefficiency and mitochondrial function impairment in skeletal muscle of type 2 diabetics.

Frequency of primary glomerular disease in northeastern China.

Most frequently reported Chinese renal biopsy data have originated from southeastern China. The present study analyzed the renal biopsy data from northeastern China. The records of 1550 consecutive native patients who were diagnosed with primary glomerular diseases (PGD) after renal biopsy at our hospital during 2005-2009 were used. These patients were divided into four age groups for stratified analysis: <15, 15-44, 45-59, and ≥60 years old. Among PGD, minimal change disease (MCD) was the most common histologically diagnosed disease (30.7%), followed by IgA nephropathy (IgAN), mesangial proliferative glomerulonephritis (MsPGN), membranous nephropathy (MN), membranoproliferative glomerulonephritis (MPGN), focal segmental glomerulosclerosis (FSGS), and endocapillary proliferative glomerulonephritis (EnPGN). MCD was the disease most frequently observed (43.7%) in the <15-year-old group. MsPGN was the most common disease in the elderly group (38.1%). MsPGN was more prevalent in females (27.8%), whereas MCD was more prevalent in males (35.3%). Primary glomerular diseases constituted the most commonly encountered group of diseases with a high prevalence of MCD, which predominantly affected males and young adults. The prevalence of MCD was high in northeastern China. Further study is necessary to expand the epidemiologic data available for renal disease in China.