Observation of three-component fermions in the topological semimetal molybdenum phosphide.

In quantum field theory, Lorentz invariance leads to three types of fermion-Dirac, Weyl and Majorana. Although the existence of Weyl and Majorana fermions as elementary particles in high-energy physics is debated, all three types of fermion have been proposed to exist as low-energy, long-wavelength quasiparticle excitations in condensed-matter systems. The existence of Dirac and Weyl fermions in condensed-matter systems has been confirmed experimentally, and that of Majorana fermions is supported by various experiments. However, in condensed-matter systems, fermions in crystals are constrained by the symmetries of the 230 crystal space groups rather than by Lorentz invariance, giving rise to the possibility of finding other types of fermionic excitation that have no counterparts in high-energy physics. Here we use angle-resolved photoemission spectroscopy to demonstrate the existence of a triply degenerate point in the electronic structure of crystalline molybdenum phosphide. Quasiparticle excitations near a triply degenerate point are three-component fermions, beyond the conventional Dirac-Weyl-Majorana classification, which attributes Dirac and Weyl fermions to four- and two-fold degenerate points, respectively. We also observe pairs of Weyl points in the bulk electronic structure of the crystal that coexist with the three-component fermions. This material thus represents a platform for studying the interplay between different types of fermions. Our experimental discovery opens up a way of exploring the new physics of unconventional fermions in condensed-matter systems.

[Histiocyte-rich rhabdomyoblastic tumor: a clinicopathological and molecular genetic analysis].

Objective: To investigate the clinicopathologic and molecular genetic characteristics, diagnosis, differential diagnosis, treatment and prognosis of histiocyte-rich rhabdomyoblastic tumor (HRRMT). Methods: The clinical data of two cases of HRRMT diagnosed in Fujian Provincial Hospital and Fujian University of Traditional Chinese Medicine Affiliated People's Hospital from 2020 to 2021 were collected. Histopathology and immunohistochemical (IHC) staining were used to assess morphological changes; the genetic changes were analyzed with next-generation sequencing. The relevant literature was reviewed. Results: Both cases showed well-defined solid nodules and soft masses. Microscopically, the tumors had a fibrous pseudocapsule with lymphocytic aggregation, and locally invaded the surrounding skeletal muscle tissue, and the tumor cells were fusiform to epithelioid with an intensive foamy histiocytic infiltrate. No necrosis or mitosis was observed. Immunophenotyping showed the tumor cells were positive for desmin, either one or both skeletal muscle markers (myogenin or MyoD1), and negative for h-caldesmon, ALK and SMA. The Ki-67 index was<5%. Using next-generation sequencing, one case was found to harbour KRAS (G12D) and MSH3 (Q470*) mutations. Conclusions: HRRMT is a newly described skeletal muscle tumor with uncertain malignant potential. Its diagnosis and differential diagnosis depend on morphologic and IHC staining. No specific molecular genetics changes have been identified so far.

Inhibitory effect of different chicken-derived lactic acid bacteria isolates on drug resistant Salmonella SE47 isolated from eggs.

Lactic Acid Bacteria (LAB) regulate and maintain the stability of healthy microbial flora, inhibit the adhesion of pathogenic bacteria and promote the colonization of beneficial micro-organisms. The drug resistance and pathogenicity of Salmonella enteritis SE47 isolated from retail eggs were investigated. Meanwhile, Enterococcus faecalis L76 and Lactobacillus salivarius LAB35 were isolated from intestine of chicken. With SE47 as indicator bacteria, the diameters of L76 and LAB35 inhibition zones were 12 mm and 8·5 mm, respectively, by agar inhibition circle method, which indicated that both of them had inhibitory effect on Salmonella, and L76 had better antibacterial effect; two chicken-derived lactic acid bacteria isolates and Salmonella SE47 were incubated with Caco-2. The adhesion index of L76 was 17·5%, which was much higher than that of LAB35 (10·21%) and SE47 (4·89%), this experiment shows that the higher the bacteriostatic effect of potential probiotics, the stronger the adhesion ability; then Caco-2 cells were incubated with different bacteria, and the survival of Caco-2 cells was observed by flow cytometry. Compared with Salmonella SE47, the results showed that lactic acid bacteria isolates could effectively protect Caco-2 cells; finally, after different bacteria incubated Caco-2 cells, according to the cytokine detection kit, the RNA of Caco-2 cells was extracted and transcribed into cDNA, then detected by fluorescence quantitative PCR, the results showed that L76 could protect Caco-2 cells from the invasion of Salmonella SE47, with less cell membrane rupture and lower expression of MIF and TNF genes. Therefore, the lactic acid bacteria isolates can effectively inhibit the adhesion of Salmonella and protect the integrity of intestinal barrier.

[Therapeutic effect of rigid permeable contact lenses on irregular astigmatism after keratoplasty].

Objective: To evaluate the clinical effect of rigid permeable contact lenses (RGPCL) in the correction of irregular astigmatism after keratoplasty. Methods: Retrospective case study. From June 2012 to December 2016, 31 patients (37 eyes) who underwent corneal transplantation were tested and fitted with RGPCL. The patients' data of primary disease, interval from keratoplasty to contact lens fitting, uncorrected visual acuity, best spectacle-corrected visual acuity, best RGPCL-corrected visual acuity, contrast visual acuity before and after RGPCL wear, corneal topography and corneal endothelium parameters before and after RGPCL wear were collected, including ocular complications and comfort of contact lenses. Results: Among the 31 patients, 24 were male and 7 were female, with age of (31.3±5.8) years. The mean interval between grafting and initial contact lens fitting was (4.6±2.3) years. Uncorrected visual acuity, best spectacle-corrected visual acuity, and best RGPCL-corrected visual acuity were 0.81±0.21, 0.54±0.13, and 0.10±0.07, respectively (t=7.170, 16.617, 17.866; all P<0.05). The average astigmatism was -5.76±2.23 D and -0.83±0.47 D before and after wearing RGPCL (t=8.531, P<0.05). After wearing RGPCL, the contrast visual acuity of 100%, 25%, 10%, and 5% was increased from 0.95±0.33, 1.18±0.21, 1.40±0.00, and 1.40±0.00 to 0.12±0.15, 0.37±0.17, 0.65±0.25, and 0.96±0.29, respectively (t=5.972, 8.473, 9.243, 5.104; all P<0. 05). There were no obvious changes of corneal endothelium parameters during the observation period. No obvious corneal allograft rejection or other complications occurred, and 94.6% (35/37) of the patients felt comfortable with wearing RGPCL. Conclusions: RGPCL wear is safe and effective in correcting irregular astigmatism after corneal transplantation. We can obtain good corrected vision and improve contrast visual acuity, especially for patients who can not wear spectacles. (Chin J Ophthalmol, 2019, 55: 413-418).

[Piperine inhibits the transformation of endothelial cells into fibroblasts].

Objective: To investigate the role of piperine on the transformation of endothelial cells into fibroblasts. Methods: Cultured human umbilical vein endothelial cells (HUVECs, 4-6 passage) were used for the main experiments. The transformation models of endothelial cells into fibroblasts were induced by transforming growth factor ß (TGF-ß) stimulation. HUVECs were divided into 6 groups: control group, TGF-ß group and 4 groups treated with various concentrations of piperine (1, 5, 10, 20 µmol/L). CKK-8 was used to detect cell proliferation. The CD31/α-smooth muscle actin (α-SMA) expression level was detected by fluorescent staining. The vascular endothelial cadherin (VE-cadherin)/vimentin expression was detected by immunofluorescence staining. RT-PCR was used detect the mRNA expressions of transformation markers. Western blot was used to detect the protein expression of snail and twist. Results: TGF-ß increased HUVECs proliferation (P<0.05), which could be significantly inhibited by 10 and 20 µmol/L of piperine, but not by 1 and 5 µmol/L of piperine. Immunofluorescence results demonstrated that TGF-ß increased HUVECs transformation to fibroblasts as shown by downregulated expression of endothelial markers CD31, VE-cadherin, and upregulated expression of α-SMA and vimentin, again, these effects could be attenuated by 10 and 20 µmol/L piperine. The expression levels of collagen type Ⅰ and type Ⅲ were significantly higher in TGF-ß group than in control group (P<0.05), significantly lower in TGF-ß+10 µmol/L piperine group and TGF-ß+20 µmol/L piperine group than in TGF-ß group (P<0.05).In addition, RT-PCR results showed that TGF-ß increased mRNA expression of transformation markers (snail1, snail2, twist1, twist2), while 10 and 20 µmol/L of piperine could significantly downregulated the mRNA expressions of these markers. The protein expression levels of snail and twist were significantly higher in TGF-ß group than in control group (both P<0.05), which was significantly lower in TGF-ß+20 µmol/L piperine group than in TGF-ß group (both P<0.05). Conclusions: Piperine can inhibit the transformation of endothelial cells into fibroblasts. This effect might be viewed as one of the potential mechanisms of reduced myocardial fibrosis post piperine treatment.

Compensated Semimetal LaSb with Unsaturated Magnetoresistance.

By combining angle-resolved photoemission spectroscopy and quantum oscillation measurements, we performed a comprehensive investigation on the electronic structure of LaSb, which exhibits near-quadratic extremely large magnetoresistance (XMR) without any sign of saturation at magnetic fields as high as 40 T. We clearly resolve one spherical and one intersecting-ellipsoidal hole Fermi surfaces (FSs) at the Brillouin zone (BZ) center Γ and one ellipsoidal electron FS at the BZ boundary X. The hole and electron carriers calculated from the enclosed FS volumes are perfectly compensated, and the carrier compensation is unaffected by temperature. We further reveal that LaSb is topologically trivial but shares many similarities with the Weyl semimetal TaAs family in the bulk electronic structure. Based on these results, we have examined the mechanisms that have been proposed so far to explain the near-quadratic XMR in semimetals.

Genes and pathways identified in thyroid carcinoma based on bioinformatics analysis.

The objective of this study was to investigate the key genes and pathways associated with thyroid carcinoma. Based on the microarray data of GSE27155, we identified the differentially expressed genes (DEGs) between four types of thyroid carcinoma samples (papillary carcinoma (PTC), oncocytic carcinoma (OTC), follicular carcinoma (FTC) and anaplastic carcinoma (ATC)) and normal controls. With the obtained DEGs, we performed gene functional interaction (FI) network analysis. Then we conducted Venn diagram analysis to identify the intersection and specific DEGs of the four types of thyroid carcinomas. The intersections DEGs were performed by functional enrichment and transcription factor (TF) prediction analyses. These specific DEGs were performed by pathway enrichment analysis. There were respectively 323, 318, 118 and 1005 DEGs identified in PTC, OTC, FTC and ATC. Twelve sub-network modules were extracted based on gene FI network analysis and eight thyroid carcinoma-associated DEGs were involved in the network, such as TIMP1. Based on the Venn diagram analysis, 27 common DEGs were identified, such as HMGB3 which was regulated by TF of NKX3-1. There were 149 PTC-specific DEGs (like CLDN1), 160 OTC-specific DEGs, 94 FTC-specific DEGs (like PPARG), and 789 ATC-specific DEGs (like CDK1). They were enriched in some pathways, such as Cell cycle, Citrate cycle, and Oxidative phosphorylation. TIMP1, HMGB3, CLDN1, CDK1 and PPARG as well as pathways of Cell cycle, Citrate cycle, and Oxidative phosphorylation may play important roles in the progression of thyroid carcinoma.

Protective effect of thymoquinone on cholestatic rats with liver injury.

The aim of this study was to investigate the protective effects of thymoquinone treatment on cholestatic rats with liver injury. Thirty-two Sprague-Dawley rats were divided randomly into four groups: normal control, bile duct ligation model control, low-dose thymoquinone (25 mg/kg), and high-dose thymoquinone (50 mg/kg). Thymoquinone gavage was administered continuously 3 days before bile duct ligation, and saline, at the same volume, was administered to the control group. The rats were sacrificed after 2 weeks of treatment, and the liver tissues were obtained and frozen. The contents of hydroxyproline (HP), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the homogenate of the liver tissues were determined to evaluate the changes in hepatic tissue pathology by fibrosis scoring. The HP and MDA levels were significantly lower and the SOD and GPx levels were significantly higher in the thymoquinone-treatment group than the corresponding levels in the model control group, and the differences were statistically significant (P < 0.05) and dose-dependent. The hepatic necrosis areas and hepatic fibrosis scores of the thymoquinone-treatment groups were significantly lower than those of the model group (P < 0.05). Thymoquinone increased the antioxidative capacity of liver and reduced the oxidative stress damage to the liver. Thymoquinone can be used as a liver protectant in patients with cholestasis.

Role of inflammatory parameters in the susceptibility of cerebral thrombosis.

We aimed to investigate the association of inflammation-related genes such as IL-10, IL-6 and IL-1B with risk of ischemic stroke. We included 426 cases with ischemic stroke and 426 health controls from Xinxiang, China. Genomic DNA was extracted from the buffy coat layer of collected blood with the TIANamp blood DNA kit. Diabetes, hypertension, obesity, and smoking habits were associated with risk of ischemic stroke. We found that individuals carrying the CC genotype of IL-1B rs1864169 had a higher risk of ischemic stroke when compared with the TT genotype (OR = 1.80, 95%CI = 1.16-2.80). The IL-6 rs1800796 TT genotype was associated with increased risk of ischemic stroke. We found that IL-1B rs1864169 and IL-6 rs1800796 polymorphisms may interact with diabetes, hypertension and obesity. Our study suggests that IL-6 rs1800796 and IL-1B rs1864169 polymorphisms are associated with ischemic stroke risk in the Chinese population.

Development and validation of a nomogram model for predicting distant metastasis of aged ≥50 patients with thyroid carcinoma: a SEER database analysis.

OBJECTIVE: This work aimed to construct and validate a model for predicting distant metastasis (DM) in thyroid carcinoma (TC) patients aged≥50. PATIENTS AND METHODS: The research data were collected from the Surveillance, Epidemiology, and End Results (SEER) program databases via SEER*Stat software (https://seer.cancer.gov/). Logistics regression was used to screen the independent risk factors for TC patients. The nomogram was constructed and validated based on the logistics regression results for predicting DM occurrence in TC patients. Moreover, the characteristic curves (ROC) were used to assess the predictive performance. The decision analysis curve (DCA) and the calibration curve were used to test this nomogram's accuracy and discrimination. Additionally, we analyzed survival and risk scores in TC patients with metastasis using the Kaplan-Meier (KM) method. RESULTS: A total of 11,166 TC patients were divided into a training set and a validation set. The results showed that topography (T), lymph node metastasis (N), and (grade) G were crucial risk factors for predicting DM. ROC analysis showed that the model had a good discriminative ability both in the training and validation set. The DCA curve showed greater net benefits across a range of DM risks for the nomogram in the training and validation set. Survival analyses showed that the metastasis cases with low-risk scores have shown a poorer prognosis in this study, both in the training and validation set. CONCLUSIONS: The nomogram model had excellent predictive performance and net benefit for predicting DM of TC patients aged ≥50. The model can help doctors develop treatment plans for their patients.

Dirac nodal surfaces and nodal lines in ZrSiS.

Topological semimetals are characterized by symmetry-protected band crossings, which can be preserved in different dimensions in momentum space, forming zero-dimensional nodal points, one-dimensional nodal lines, or even two-dimensional nodal surfaces. Materials harboring nodal points and nodal lines have been experimentally verified, whereas experimental evidence of nodal surfaces is still lacking. Here, using angle-resolved photoemission spectroscopy (ARPES), we reveal the coexistence of Dirac nodal surfaces and nodal lines in the bulk electronic structures of ZrSiS. As compared with previous ARPES studies on ZrSiS, we obtained pure bulk states, which enable us to extract unambiguously intrinsic information of the bulk nodal surfaces and nodal lines. Our results show that the nodal lines are the only feature near the Fermi level and constitute the whole Fermi surfaces. We not only prove that the low-energy quasiparticles in ZrSiS are contributed entirely by Dirac fermions but also experimentally realize the nodal surface in topological semimetals.

Construction of a ptfA chitosan nanoparticle DNA vaccine against Pasteurella multocida and the immune response in chickens.

The aim of this study was to evaluate the effect of chitosanon the immune response induced by a DNA vaccine based on the ptfA gene of avian Pasteurella multocida. Naked DNA vaccine was packed with chitosanmolecules, resulting in a chitosannanoparticle DNA vaccine. The encapsulation efficiency, shape, size and resistance to DNA degradation were determined. The vaccine was administered to chickens and serum antibody, interferon-γ (IFN-γ), interleukin-2 (IL-2) and interleukin-4 (IL-4) concentrations were determined and lymphocyte proliferation assays were performed. After challenge with virulent avian P. multocida, protective efficacy was evaluated. The encapsulation efficiency of the chitosan nanoparticle DNA vaccine was 95.3%. The particle size was approximately 200nm and close to spherical in shape and it could effectively resist degradation by DNases. Following vaccination, serum antibodies, stimulation index (SI) value and concentrations of IFN-γ and IL-2 in chickens vaccinated with the chitosan nanoparticle DNA vaccine were significantly higher than those that were vaccinated with the naked DNA vaccine (P-values are 0.026, 0.045, 0.039 and 0.024, respectively). However, the concentrations of IL-4 in the two DNA vaccines group were no significant difference (P=0.157). The protective efficacy rate provided by naked DNA vaccine, chitosan nanoparticle DNA vaccine and the attenuated live vaccine were 56%, 68% and 88%, respectively. The results indicated that chitosan was able to enhance the immune response to a naked DNA vaccine based on the ptfA gene of P. multocida.

Electronic structure of SrSn2As2 near the topological critical point.

Topological materials with exotic quantum properties are promising candidates for quantum spin electronics. Different classes of topological materials, including Weyl semimetal, topological superconductor, topological insulator and Axion insulator, etc., can be connected to each other via quantum phase transition. For example, it is believed that a trivial band insulator can be twisted into topological phase by increasing spin-orbital coupling or changing the parameters of crystal lattice. With the results of LDA calculation and measurement by angle-resolved photoemission spectroscopy (ARPES), we demonstrate in this work that the electronic structure of SrSn2As2 single crystal has the texture of band inversion near the critical point. The results indicate the possibility of realizing topological quantum phase transition in SrSn2As2 single crystal and obtaining different exotic quantum states.

Simultaneous determination of nine saponins from Panax notoginseng using HPLC and pressurized liquid extraction.

A HPLC and pressurized liquid extraction (PLE) method was developed for simultaneous determination of nine saponins, including notoginsenoside R1, ginsenoside Rg1, Re, Rf, Rb1, Rc, Rb2, Rb3 and Rd in Panax notoginseng. The analysis was performed on C18 column with water-acetonitrile gradient elution and the investigated saponins were authenticated by comparing retention time and mass spectra with their reference compounds. Several methods including PLE, ultrasonication, soxhlet extraction and immersion were used for sample preparation and their extraction efficiency was compared. The results showed that PLE has the highest extraction efficiency and repeatability, which would be valuable on standardization of sample preparation for quality control of Chinese medicines. The developed HPLC and PLE is an effective approach for simultaneously quantitative determination of sapoinins in P. notoginseng, which could be used for quality control of P. notoginseng and its preparations.

Ordered fragmentation of oxide thin films at submicron scale.

Crack formation is typically undesirable as it represents mechanical failure that compromises strength and integrity. Recently, there have also been numerous attempts to control crack formation in materials with the aim to prevent or isolate crack propagation. In this work, we utilize fragmentation, at submicron and nanometre scales, to create ordered metal oxide film coatings. We introduce a simple method to create modified films using electroplating on a prepatterned substrate. The modified films undergo preferential fragmentation at locations defined by the initial structures on the substrate, yielding ordered structures. In thicker films, some randomness in the characteristic sizes of the fragments is introduced due to competition between crack propagation and crack creation. The method presented allows patterning of metal oxide films over relatively large areas by controlling the fragmentation process. We demonstrate use of the method to fabricate high-performance electrochromic structures, yielding good coloration contrast and high coloration efficiency.

Synergistic neurotoxic effects of combined treatments with cytokines in murine primary mixed neuron/glia cultures.

Activation of brain glial cells with the bacterial endotoxin lipopolysaccharide (LPS), the HIV-1 coat protein gp120, or beta-amyloid-derived peptides, stimulates the expression of several cytokines, including tumor necrosis factor-alpha (TNFalpha), interleukin-1 (IL-1) and IL-6. and nitric oxide (NO) which have been proposed as causes of neurodegeneration in the brain. In the present study, the neurotoxic effects of several cytokines, alone or in various combinations, and the correlations of the release of lactate dehydrogenase, the loss of neurons, and the secretion of NO in brain neuronal cell injury were investigated in murine primary mixed neuronal/glial cell cultures. A specific combination of cytokines, i.e., IL-1 (1 ng/ml)+ TNFalpha (10 ng/ml)/interferon-gamma (IFNgamma) (200 u/ml), induced a dramatic neuronal cell injury in the neuron/glia cultures, and its cytotoxic profile was very similar to that seen with the LPS/IFNgamma-induced neuron injury. This indicates that among the many toxic immune mediators secreted in response to LPS, IL-1 and TNFalpha can mimic LPS as the triggering signals and primary mediators for glia-mediated neuron injury in the presence of IFNgamma. This study provides new insights about the cytotoxic mechanism(s) for cytokine-mediated neuron injury.

beta-Endorphin enhances the replication of neurotropic human immunodeficiency virus in fetal perivascular microglia.

The effect of an endogenous opiate, beta-endorphin, on the replication of HIV was investigated in brain perivascular microglia. Beta-endorphin enhanced the synthesis of p-24 antigen and transactivation of HIV promoter. Dialysed culture supernatants of endorphin-treated microglia re-activated latent HIV infection. These culture supernatants showed elevated levels of interleukin-1 beta, IL-6 and tumor necrosis factor alpha. Sub-optimal concentration of beta-endorphin potentiated GP-120-induced synthesis of these cytokines. Nalaxone reversed beta-endorphin-induced, but not GP-120-induced, cytokine production and enhanced HIV replication. These results suggest that endogenous opiates may contribute to the progression of AIDS dementia complex.

Reduction of lipopolysaccharide-induced neurotoxicity in mixed cortical neuron/glia cultures by femtomolar concentrations of pituitary adenylate cyclase-activating polypeptide.

Stimulation of murine primary mixed cortical neuron/glia cultures with lipopolysaccharide, an endotoxin, was used as a model for inflammatory disorders of the central nervous system. Lipopolysaccharide (20 microg/ml) increased the secretion of lactate dehydrogenase, a marker for cell injury, and nitric oxide into the culture medium. The lipopolysaccharide-induced release of lactate dehydrogenase into the culture medium was reduced by pituitary adenylate cyclase-activating polypeptide (PACAP) at 10(-14)-10(-12) M. The 27- and 38-amino-acid forms of PACAP were equipotent and their dose-response curves were U-shaped. PACAP6-38, a specific type I PACAP receptor antagonist, blocked the reduction by PACAP38 of the lipopolysaccharide-induced release of lactate dehydrogenase. The lipopolysaccharide-induced secretion of nitric oxide into the culture medium was reduced by PACAP at 10(-14)-10(-12) M and 10(-8)-10(-6) M. The 27- and 38-amino-acid forms of PACAP were equipotent. PACAP6-38 blocked the reduction of the lipopolysaccharide-induced secretion of nitric oxide by PACAP38 at 10(-12) M, but not at 10(-8) M. Vasoactive intestinal polypeptide reduced the lipopolysaccharide-induced release of lactate dehydrogenase into the culture medium at 10(-14)-10(-12) M, but these concentrations of vasoactive intestinal polypeptide had no effect on the lipopolysaccharide-induced secretion of nitric oxide. PACAP6-38 did not effect the reduction of the lipopolysaccharide-induced release of lactate dehydrogenase into the culture medium by 10(-12) M vasoactive intestinal polypeptide. These results indicate that stimulation of type I PACAP receptors by femtomolar concentrations of PACAP can prevent neuron death in a model for inflammatory disorders of the CNS. These results suggest that PACAP is also an extraordinarily potent inhibitor of some microglial functions.