[Determination and significance of serum MPO and amylin in adult patients with OSAHS after short-range noninvasive positive pressure ventilation]

Objective:The aim of this study to investigate the determination and significance of serum MPO and amylin in adult patients with OSAHS after short-range noninvasive positive pressure ventilation. Method:Eighty-seven OSAHS patients were divided into severe group (30 cases), moderate group (30 cases) and mild group (27 cases) according to the AHI range. Twenty-seven outpatient health persons were selected as the control group. Serum amylin and myeloperoxidase were measured by ELISA; Amyloid and myeloperoxidase were reassessed in 30 patients with severe OSAHS after 6 months of combined therapy, and the relationship between amylin, myeloperoxidase and PSG was analyzed. Result:①With the severity of OSAHS patients increased, the serum amylin and myeloperoxidase levels gradually increased (F=22.486, 19.755;P<0.01); There was no significant difference in MPO and amylin concentration between the mild group and the control group (P>0.05), and the other groups were significantly different from each other (P<0.01). ②There was no correlation among serum amylin and myeloperoxidase level and BMI and age in OSAHS patients (P>0.05); and a negative correlation with SaO₂, and AHI was positively correlated (P<0.01). ③After 3 months of CPAP treatment, LSaO₂ increased which the AHI and peripheral blood MPO, amylin levels lower than before in 30 patients (P<0.05); The amylin and myeloperoxidase concentrations of blood after 6 months of treatment were significantly lower than those of 3 months after treatment (P<0.05), which still increased compared with the control group. Conclusion:The determination of serum amylin and MPO in patients with OSAHS has a certain reference value in predicting the condition and curative effect of diabetes mellitus and insulin resistance. CPAP treatment can significantly reduce the degree of hypoxiapatients and cardiovascular damage in OSAHS patients, which was significantly correlated with the treatment time.

[Diagnostic value of enhanced CT/MRI for thyroid cartilage invasion by malignant tumor]

Objective: To evaluate the values of enhanced CT and MRI for the diagnosis of thyroid cartilage invasion by laryngeal and hypopharyngeal cancer. Methods: One hundred and ninety-seven patients with primary laryngeal or hypopharyngeal cancer treated with surgery between January 2013 and December 2014 were included in this study. All patients underwent enhanced CT and MRI before surgery. With MRI using the techniques of fast recovery fast spin echo (FRFSE), spin echo echo planar imaging (SE-EPI) and diffusion weighted imaging (DWI), thyroid cartilage invasion was evaluated and the results of postoperative histopathological examination was used as a gold standard for the determination of thyroid cartilage invasion. The sensitivity, specificity, positive predictive value and negative predictive value of enhanced CT or MRI in detecting thyroid cartilage invasion by laryngeal and hypopharyngeal cancer were evaluated. Data were analyzed with SPSS17.0 software. Results: Among 197 patients, there were 35 cases with supraglottic laryngeal cancer, 92 cases with glottic laryngeal cancer, 9 cases with subglottic laryngeal cancer, and 61 cases with hypopharyngeal cancer. Postoperative pathologycal examinations showed that 63 (32.0%) of 197 patients had thyroid cartilage invasion by tumor. Based on TNM classification of AJCC (American Joint Commission for Cancer, 2010), there were 36 cases at T2 stage, 109 cases at T3 and 52 cases at T4; 117 cases with N0, 46 cases with N1 and 34 cases with N2. The sensitivity, specificity, positive predictive value and negative predictive value of CT for the detection of thyroid cartilage invasion were respectively 57%, 86%, 65% and 81%, and those of MRI were respectively 94%, 87%, 78% and 97%. Kappa values were 0.45 for CT and 0.77 for MRI in diagnosis of thyroid cartilage invasion, with statistically significant difference (χ(2)=6.78, P<0.05). Conclusion: MRI (FRFSE and SE-EPI DWI) has more advantages than CT in the diagnosis of thyroid cartilage invasion by laryngeal or hypopharyngeal cancer.

Validation of aspirin response-related transcripts in patients with coronary artery disease and preliminary investigation on CMTM5 function

Aspirin is widely used in the prevention of cardiovascular diseases, but the antiplatelet responses vary from one patient to another. To validate aspirin response related transcripts and illustrate their roles in predicting cardiovascular events, we have quantified the relative expression of 14 transcripts previously identified as related to high on-aspirin platelet reactivity (HAPR) in 223 patients with coronary artery disease (CAD) on regular aspirin treatment. All patients were followed up regularly for cardiovascular events (CVE). The mean age of our enrolled population was 75.80±8.57years. HAPR patients showed no significant differences in terms of co-morbidities and combined drugs. Besides, the relative expression of HLA-DQA1 was significantly lower in low on-aspirin platelet reactivity (LAPR) patients, when compared with HAPR and high normal (HN) group (p=0.028). What's more, the number of arteries involved, HAPR status and the relative expression of CLU, CMTM5 and SPARC were independent risk factors for CVE during follow up (p<0.05). In addition, overexpression of CMTM5 attenuated endothelial cells (ECs) migration and proliferation, with significantly decreased phosphorylated-Akt levels, while its inhibition promoted these processes in vitro (p<0.05).Our study provides evidence that circulating transcripts might be potential biomarkers in predicting cardiovascular events. CMTM5 might exert anti-atherosclerotic effects via suppressing migration and proliferation in the vessel wall. Nevertheless, larger-scale and long-term studies are still needed.

[A new method to orthodontically correct dental occlusal plane canting: wave-shaped arch]

OBJECTIVE

To introduce a technique of second order wave-shaped arch wire to orthodontically treat dental occlusal plane canting (DOPC) with left-right interactive anchorage, and to test its clinical efficacy.

METHODS

Among the permanent dentition malocclusion patients who showed no obvious facial asymmetry, we screened for patients who showed anterior occlusal plane canting (AOPC) after routine orthodontic examination, treatment planning, MBT fixed appliance installation and serial arch wires alignment. Each patient had been clinically appraised in frontal view by 2 orthodontists and the patient him/herself; if all 3 agreed that the AOPC was obvious, the patient was included. By this means, we included 37 patients, including 10 males and 27 females; the average age was (21.9±5.2) years. To correct AOPC, opposite direction equal curvature second order rocking-chair curve was bent on each side of 0.46 mm×0.56 mm stainless steel edgewise wire. With reference to normal occlusal plane, a curve toward the occlusal surface was made to extrude under-erupted teeth on one side while a curve toward the gingiva was made to intrude over-erupted teeth on the other side, so that the arch wire was made into a wave shape in vertical dimension. Before and after application of wave-shaped arch wire, frontal facial photographs were taken when the patient's mouth was open slightly with lips retracted to show anterior occlusal plane (AOP) clearly. An AOP was constructed by connecting the center of the slot in the medial edge of canine bracket on each side in the photograph. The angles between the bipupillary plane(BPP) and the constructed AOP were measured in ImageJ1-48v software and the angle differences before and after treatment were compared with paired Wilcoxon test in SPSS 10.0 software.

RESULTS

The wave-shaped arch could correct AOPC effectively in 3 to 10 months time with an average of 5.5±1.7 months; the angles between AOP and BBP before treatment ranged from 2.90° to 6.12° with a median of 4.01°; after treatment the angles were from -0.17° to 2.57° with a median of 1.87°, the decrease of the angles between AOP and BBP after treatment ranged from 1.08° to 4.15° with a median of 2.21°. Paired Wilcoxon test P was 0.000.

CONCLUSION

The wave-shaped arch can be used independently or in combination with other treatment methods, which can take advantage of left and right interactive anchorage to correct AOPC effectively, so it has certain application value in clinical practice.

[An adolescent with Hashimoto's encephalopathy after surgery and ¹³¹I radiotherapy for papillary thyroid carcinoma: one case report]

Hashimoto's encephalopathy is a rare brain disease. Its etiology is still unknown. In this paper, we reported a 15-year-old female patient underwent total thyroidectomy and lymph node dissection, due to a multifocal papilliferous carcinoma of the right lobus. Forty-two days after surgery, the patient was treated by ¹³¹I radiotherapy in another hospital and begun to have a headache after 48 hours. At last, the patient was diagnosed by HE on the basis of all considerations. She recovered from by i.v. Immunoglobulin. Till now, the patient has not relapsed for more than 4 years follow-up.

Incoherence-coherence crossover and low-temperature Fermi-liquid-like behavior in AFe2As2 (A = K, Rb, Cs): evidence from electrical transport properties

We study the normal-state transport properties of AFe2As2 (A  =  K, Rb and Cs) single crystals using Hall coefficient, resistivity and magnetoresistance (MR) measurements. In all three materials, the Hall coefficient R H shows a strong temperature dependence, which is typical for multi-band systems. In particular, R H develops an upturn below a characteristic temperature [Formula: see text], which is in agreement with the incoherence-coherence crossover reported in recent nuclear magnetic resonance studies. A Fermi-liquid-like state, characterized by T (2) behavior of the resistivity and a positive orbital MR obeying Kohler's rule, emerges below T FL  ∼0.4 [Formula: see text]. The superconducting transition temperature T c experiences a simultaneous suppression with [Formula: see text] and T FL as the alkali ion's radius increases from A  =  K to A  =  Cs, suggesting that the unconventional superconductivity in the AFe2As2 series is related to the strength of the electronic coherence. A phase diagram, similar to that in the heavy fermion Kondo lattice system, is obtained. Based on all the experimental evidence, we argue that the physical properties of this family of heavily hole-doped Fe-based superconductors are controlled by the hybridization between itinerant carriers and localized orbitals, and the Kondo scenario could be effective in such a case.

Resolving and Tuning Mechanical Anisotropy in Black Phosphorus via Nanomechanical Multimode Resonance Spectromicroscopy

Black phosphorus (P) has emerged as a layered semiconductor with a unique crystal structure featuring corrugated atomic layers and strong in-plane anisotropy in its physical properties. Here, we demonstrate that the crystal orientation and mechanical anisotropy in free-standing black P thin layers can be precisely determined by spatially resolved multimode nanomechanical resonances. This offers a new means for resolving important crystal orientation and anisotropy in black P device platforms in situ beyond conventional optical and electrical calibration techniques. Furthermore, we show that electrostatic-gating-induced straining can continuously tune the mechanical anisotropic effects on multimode resonances in black P electromechanical devices. Combined with finite element modeling (FEM), we also determine the Young's moduli of multilayer black P to be 116.1 and 46.5 GPa in the zigzag and armchair directions, respectively.

[The diagnosis and treatment strategy for patients with severemultispace abscesses in neck]

Objective:To analyze the clinical characteristics of patients with severe deep neck abscess,etiology,imaging,appropriate treatment selection in those patients,to improve the judgement and understanding of the disease.Method:Thirty cases of severe deep neck abscess treated from March 2010 to June 2015 were retrospectively reviewed,including the clinical characteristics,diagnosis and treatment strategy.Result:The sore throat,odynophagia,dysphagia,fever and difficulty breathing were the most common symptoms of severe deep neck abscess.The causes of deep neck abscess were tooth diseases(5 cases),foreign bodies in pharynx or esophagus(4 cases),the second branchial crack cyst with multiply abscess,uncertain cause(20 cases).Six of the above cases complicated with mediastinal abscess.Radiologic evaluation was performed on all of the patients to identify the most probable location of the abscess:parapharyngeal space,retropharyngeal space,masticator space,carotid space,etc.Twenty-five cases were treated by drainage via incising lateral neck and 4 patientsreceived abscess puncture aspiration.Life-threatening complications were developed in all cases,29 cases were cured but one case dead.Conclusion:The treatment of severe deep neck multispace abscesses should be mindful.Once deep neck abscesses are diagnosed,we should timely undertake surgical drainage via incising lateral neck.Emergency tracheostomy should be perform in some case like severe dyspnea,airway obstrucion.Antibiotics should be appropriately applied,and basic diseases and complications should be carefully controlled.

[Frequency and clinical features of ASXL2 gene mutation in acute myeloid leukemia patients with AML1- ETO fusion gene positive]

目的

探讨伴AML1-ETO融合基因的急性髓系白血病（AML）患者ASXL2基因突变情况、突变阳性患者临床特征及ASXL2基因突变与c-kit基因突变的关系。

方法

采用PCR扩增产物片段直接测序分析法，检测59例伴AML1-ETO融合基因初发AML患者ASXL2基因第11、12外显子编码区突变情况，比较ASXL2基因突变阳性和阴性组患者的临床特征、生存及c-kit基因突变情况。

结果

59例患者中7例存在ASXL2突变，突变率为11.9%。ASXL2基因突变阳性组患者初诊时外周血红蛋白浓度中位数为56.2（38.0~72.0）g/L，显著低于ASXL2突变阴性组患者的69.0（37.2~154.0）g/L，差异有统计学意义（P=0.038）；外周血WBC、PLT、嗜酸粒细胞比例、骨髓原始细胞比例与ASXL2突变阴性组相比，差异均无统计学意义（P值均>0.05）。两组均未见肝、脾、中枢神经系统浸润；淋巴结不同程度肿大，但ASXL2基因突变阳性、阴性两组间差异无统计学意义（P=0.859）。免疫表型分析显示：ASXL2基因突变阳性组CD33表达显著低于阴性组（P=0.033）；两组患者均未表达cCD3，CD117、cMPO、HLA-DR、CD34、CD38、CD13、CD44、CD15、CD64、CD11b、CD56、CD19、cCD79a、CD7两组表达差异均无统计学意义（P值均>0.05）。ASXL2基因突变阳性与阴性组患者总缓解率、总生存时间差异均无统计学意义（P值分别为0.577、0.631）。两组c-kit基因突变检出率分别为14.3％和29.4%，差异无统计学意义（P=0.697）。

结论

该组伴AML1-ETO融合基因AML患者ASXL2基因突变率为11.9%。ASXL2突变阳性患者外周血红蛋白浓度、CD33表达方面呈现一定的临床特征。ASXL2基因突变与c-kit基因变突可能没有特定的关联性。

Syphilitic dementia and lipid metabolism

BACKGROUND AND PURPOSE

Chronic syphilitic infection may lead to dementia. It is in general paresis (GP), which is the major late form of neurosyphilis, that cognitive impairment frequently occurs. The association between lipid metabolism and GP is unclear.

METHODS

In this study, serum lipids were studied in 188 GP patients, in 241 syphilitic patients without neurosyphilis and in 539 healthy controls. The Mini-Mental State Examination (MMSE) was tested in all GP patients. Thirty-five GP patients had a follow-up evaluation 3 months after penicillin treatment.

RESULTS

Significantly lower apolipoprotein A-I (apoA-I) levels were found in GP and in syphilitic patients without neurosyphilis compared to controls. In the 25-44-year-old groups, the male syphilitic patients without neurosyphilis had lower serum apoA-I levels and higher apolipoprotein B (apoB)/apoA-I ratios compared with female patients. A follow-up evaluation of 35 GP patients 3 months after penicillin treatment showed a significant positive correlation between increased apoA-I levels and MMSE scores.

CONCLUSION

Abnormal apoA-I metabolism may be associated with the decline of cognitive performance. Long-term decrease of apoA-I level and higher apoB/apoA-I ratio may be contributing factors in syphilitic dementia. These results suggest a similar overlap between syphilitic dementia and lipid metabolism to that occurring in Alzheimer's disease.

Serum uric acid level and left ventricular hypertrophy in elderly male patients with nonvalvular atrial fibrillation

BACKGROUND AND AIMS

Recent studies have suggested that serum uric acid (SUA) induces oxidative stress and inflammation, which are involved in the mechanism of cardiac hypertrophy. In patients with atrial fibrillation (AF), comorbidity of left ventricular hypertrophy (LVH) exacerbates cardiac function. In this study, we investigated the association between SUA and cardiac hypertrophy in AF patients.

METHODS AND RESULTS

Initially, 1296 consecutive elderly patients (age >60) with nonvalvular AF were retrospectively selected from the inpatient clinic between January 2012 and April 2015. Demographic, clinical, and echocardiographic characteristics were carefully recorded. The final study population was 577 patients. The mean SUA level was significantly higher in patients with LVH than those without LVH. Compared with the non-LVH group, the LVH group was older, had a higher percentage of female patients, and had lower hemoglobin levels and estimated glomerular filtration rates. Patients in the LVH group also had a higher rate of coronary heart disease and fewer had history of radiofrequency ablation compared with the non-LVH group. In the hyperuricemia group, B-type natriuretic peptide levels, left atrial diameter, left ventricular mass index, and percentage of NYHA (New York Heart Association) class III/IV were significantly higher than the SUA normal group. Multivariate logistic regression analysis indicated the independent risk factors for LVH in elderly AF patients included SUA, age, male sex, the presence of coronary heart disease, and diuretic therapy. Subgroup analysis identified SUA as a significant risk factor associated with LVH in men.

CONCLUSIONS

SUA was independently associated with LVH in elderly male patients with nonvalvular AF.

[Small doses of gentamicin drum indoor injection treatment of intractableMénière disease clinical observation of the impact of the hearing]

Objective:To investigate the history,audiology,imaging,and operative characteristics of tympanosclerosis patients with intact tympanic membranes,and to provide theoretical reference for preoperative diagnosis and treatment.Method:A retrospective study was carried out among 9 tympanosclerosis patients (16 ears) with intact tympanic membranes who underwent exploratory tympanotomy.For different patients,the different reconstruction of ossicular chain are in selection.We compared the pre-operative outcomes of pure tone audiometry and otoscope with the post-operative outcomes,and calculated their air-bone gap and improvement value.Result:At 3 month after operation,otoscope showed that the tympanic membrane of all patiens were integrity.Tinnitus disappeared or improved in 5 cases.The mean thresholds of air conduction,bone conduction and air-bone gap were(40.33±11.48)dB,(27.34±8.46)dB,(13.16±9.85)dB respectively.The air-bone gap in 3 months after the operation was significantly smaller than that before operation(P<0.05).Conclusion:Most of the patients with tympanosclerosis suffer mixed hearing loss.In addition to chronic inflammatory stimulation,tympanic membrane incision catheter may be one of the important pathogenic factors.Morphology and imaging are more useful in differentiation of otosclerosis.Early and active surgery interference would attain good effect.

Bulk Fermi Surface of Charge-Neutral Excitations in SmB_{6} or Not: A Heat-Transport Study

Recently, there have been increasingly hot debates on whether a bulk Fermi surface of charge-neutral excitations exists in the topological Kondo insulator SmB_{6}. To unambiguously resolve this issue, we perform the low-temperature thermal conductivity measurements of a high-quality SmB_{6} single crystal down to 0.1 K and up to 14.5 T. Our experiments show that the residual linear term of thermal conductivity at the zero field is zero, within the experimental accuracy. Furthermore, the thermal conductivity is insensitive to the magnetic field up to 14.5 T. These results demonstrate the absence of fermionic charge-neutral excitations in bulk SmB_{6}, such as scalar Majorana fermions or spinons and, thus, exclude the existence of a bulk Fermi surface suggested by a recent quantum oscillation study of SmB_{6}. This puts a strong constraint on the explanation of the quantum oscillations observed in SmB_{6}.

[Discovery of a novel spliceosome of ABL gene (ABL(Δexon7+35INS)) and its association with TKIs resistance in chronic myeloid leukemia]

OBJECTIVE

To explore whether the ABL(Δexon7) and ABL(35INS) spliceosome contributed to TKIs resistance.

METHODS

Screening ABL(Δexon7) and ABL(35INS) in 74 normal people and 76 CML patients (53 patients in remission and 23 patients with TKIs resistance) by using polyacrylamide gel electrophoresis combined with cloning sequencing.

RESULTS

A novel spliceosome ABL(Δexon7+ 35INS) (ABL(Δexon7) and ABL(3)5INS existed at the same time) was identified and the mutation was detected in 8 (10.8%) of 74 normal people, 4 (7.5%) of 53 remission patients and 2 (8.7%) of 23 resistant patients. While 47 (63.5%) cases expressed ABL(Δexon7) and 8 (10.8% ) cases expressed ABL(35INS) in 74 healthy people, 30 (56.6%) cases expressed ABL(Δexon7) and 5 (9.4% ) cases expressed ABL(35INS) in 53 remission patients, 12 (52.2%) cases expressed ABL(Δexon7) and 3(13.0%) cases expressed ABL(35INS) in 23 resistant patients. Three kinds of spliceosome in all groups had no statistical difference.

CONCLUSION

ABL(Δexon7+ 35INS), ABL(Δexon7) and ABL(35INS) may be not uncommon in ABL gene and were unrelated to resistance in CML with TKIs treatment. ABL(35INS) were often accompanying with exon 7 deletion.

Identification of novel DYNC2H1 mutations associated with short rib-polydactyly syndrome type III using next-generation panel sequencing

Short rib-polydactyly syndrome type III (SRPS3) is a perinatal lethal skeletal disorder with polydactyly and multisystem organ abnormalities. While ultrasound of the fetus can detect skeletal abnormalities characteristic of SRPS3, the syndrome is often difficult to diagnose before birth. As SRPS3 is an autosomal recessive disorder, identification of the gene mutations involved could lead to the development of prenatal genetic testing as an accurate method of diagnosis. In this study, we describe genetic screening approaches to identify potential abnormalities associated with SRPS3. Karyotype analysis, array comparative genomic hybridization (aCGH), and next-generation panel sequencing were each performed on a fetus showing signs of the disorder, as well as on the mother and father. Karyotype and aCGH results revealed no abnormalities. However, next-generation panel sequencing identified novel mutations in the DYNC2H1 gene. The fetus was compound heterozygous for both a missense mutation c.8313A > T and a frameshift mutation c.10711_10714delTTTA in the DYNC2H1 gene, which were inherited from the mother and father, respectively. These variants were further confirmed using Sanger sequencing and have not been previously reported. Our study indicates the utility of using next-generation panel sequencing in screening for novel disease-associated mutations.

Emergent Kondo Lattice Behavior in Iron-Based Superconductors AFe_{2}As_{2} (A=K, Rb, Cs)

Here, we experimentally study the origin of d-electron heavy fermion (HF) behavior in iron-based superconductors (FeSCs) AFe_{2}As_{2} (A=K, Rb, Cs). Nuclear magnetic resonance on ^{75}As reveals a universal coherent-incoherent crossover with a characteristic temperature T^{*}. Below T^{*}, a so-called "Knight shift anomaly" is first observed in FeSCs, which exhibits a scaling behavior similar to f-electron HF materials. Furthermore, the scaling rule also regulates the manifestation of magnetic fluctuation. These results undoubtedly support an emergent Kondo lattice scenario for the d-electron HF behavior, which qualifies the AFe_{2}As_{2} (A=K, Rb, Cs) as d-electron HF superconductors.

Ultralow-Frequency Collective Compression Mode and Strong Interlayer Coupling in Multilayer Black Phosphorus

The recent renaissance of black phosphorus (BP) as a two-dimensional (2D) layered material has generated tremendous interest, but its unique structural characters underlying many of its outstanding properties still need elucidation. Here we report Raman measurements that reveal an ultralow-frequency collective compression mode (CCM) in BP, which is unprecedented among similar 2D layered materials. This novel CCM indicates an unusually strong interlayer coupling, and this result is quantitatively supported by a phonon frequency analysis and first-principles calculations. Moreover, the CCM and another branch of low-frequency Raman modes shift sensitively with changing number of layers, allowing an accurate determination of the thickness up to tens of atomic layers, which is considerably higher than previously achieved by using high-frequency Raman modes. These findings offer fundamental insights and practical tools for further exploration of BP as a highly promising new 2D semiconductor.

Evolution of High-Temperature Superconductivity from a Low-T_{c} Phase Tuned by Carrier Concentration in FeSe Thin Flakes

We report the evolution of superconductivity in an FeSe thin flake with systematically regulated carrier concentrations by the liquid-gating technique. With electron doping tuned by the gate voltage, high-temperature superconductivity with an onset at 48 K can be achieved in an FeSe thin flake with T_{c} less than 10 K. This is the first time such high temperature superconductivity in FeSe is achieved without either an epitaxial interface or external pressure, and it definitely proves that the simple electron-doping process is able to induce high-temperature superconductivity with T_{c}^{onset} as high as 48 K in bulk FeSe. Intriguingly, our data also indicate that the superconductivity is suddenly changed from a low-T_{c} phase to a high-T_{c} phase with a Lifshitz transition at a certain carrier concentration. These results help to build a unified picture to understand the high-temperature superconductivity among all FeSe-derived superconductors and shed light on the further pursuit of a higher T_{c} in these materials.

Angular-Dependent Phase Factor of Shubnikov-de Haas Oscillations in the Dirac Semimetal Cd_{3}As_{2}

We measure the magnetotransport properties of the three-dimensional Dirac semimetal Cd_{3}As_{2} single crystal under magnetic fields up to 36 T. Shubnikov-de Haas (SdH) oscillations are clearly resolved and the n=1 Landau level is reached. A detailed analysis on the intercept of the Landau index plot reveals a significant dependence of the SdH phase factor on the orientation of the applied magnetic field. When the magnetic field is applied in the [001] direction, i.e., along the fourfold screw axis of the tetragonal crystal structure, a nontrivial π Berry phase, as predicted for the Dirac fermions, is observed. However, in a magnetic field tilted away from the [001] direction, the π Berry phase is evidently reduced, and a considerable enhancement of the effective mass is also revealed. Our observations demonstrate that the Dirac dispersion in Cd_{3}As_{2} is effectively modified in a tilted magnetic field, whereas the preserved π Berry phase in a magnetic field along the [001] direction can be related to the realization of the Weyl fermions. The sudden change of the SdH phase also indicates a possible topological phase transition induced by the symmetry-breaking effect.

Pressure-Induced Electronic Transition in Black Phosphorus

In a semimetal, both electrons and holes contribute to the density of states at the Fermi level. The small band overlaps and multiband effects engender novel electronic properties. We show that a moderate hydrostatic pressure effectively suppresses the band gap in the elemental semiconductor black phosphorus. An electronic topological transition takes place at approximately 1.2 GPa, above which black phosphorus evolves into a semimetal state that is characterized by a colossal positive magnetoresistance and a nonlinear field dependence of Hall resistivity. The Shubnikov-de Haas oscillations detected in magnetic field reveal the complex Fermi surface topology of the semimetallic phase. In particular, we find a nontrivial Berry phase in one Fermi surface that emerges in the semimetal state, as evidence of a Dirac-like dispersion. The observed semimetallic behavior greatly enriches the material property of black phosphorus and sets the stage for the exploration of novel electronic states in this material.

Analysis of skin color change and related gene expression after crossing of Dongxiang black chicken and ISA layer

This study evaluated the effects of the autosomal domi-nant Fm gene in conjunction with the sex-linked Id gene on skin color and related gene expression. Ten Dongxiang black cocks were selected to build ten families by mating 60 individuals of ISA B-line layers. The skin color of the F1 generation was observed at different time points. At 126 days, 36 chickens were slaughtered, and gene expression of TYRP1, TYRP2, MC1R, and EDNRB in breast skin was assessed by quantitative RT-PCR. The ratio of Dongxiang black chickens with white skin chicks in the F1 generation to that of non-white was 3:7 (HoFF: HeFf). At 126 days, all F1 generation cocks showed white skin (115/115), while the percentages of hens with black skin were 100% (HoFF, 27/27) and 53.75% (HeFf, 43/80). The change in skin color peaked between 42 and 84 days. The offspring of HoFF displayed significantly higher expres-sion of MC1R, compared with those of HeFf (P < 0.05). The "L" value of hen's skin was significantly lower, and TYRP1 and TYRP2 expres-sion was significantly higher (P < 0.05) than in cocks with the same Fm/fm genotype. These findings indicate the presence of homozygous and heterozygous Fm in Dongxiang black chickens, with the offspring of homozygous birds showing a higher percentage of black skin percentage. The expression of the four genes studied was correlated with skin color, with TYRP1 and TYRP2 representing the most suitable molecular markers.