[Microwave ablation versus radiofrequency ablation for solid or predominantly solid benign thyroid nodules: a randomized controlled clinical trial]

Objective: To compare the short-term efficacy and the safety of microwave ablation (MWA) and radiofrequency ablation (RFA) in the treatment of benign thyroid nodules (BTNs). Methods: This prospective randomized controlled trial, performed from December 2019 to September 2021, included 36 patients with solid or predominantly solid BTNs who met the eligibility criteria and provided written informed consent at the Nanjing sub-center (Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine). Patients were assigned to either the MWA group or the RFA group (18 patients in each group) at a ratio of 1∶1 using a block randomization design and allocation concealment using sealed envelope randomization. The independent-sample t-test and χ2 test were used to compare the volume reduction rates (VRRs), effective rates (VRRs≥50%), cosmetic scores, and complication rates at 1, 3, and 6 months after treatment between the two groups. Results: The clinical characteristics of the two groups of patients were comparable. After ablation, the nodule volume was significantly reduced in both groups. At 1, 3, and 6 months, there was no significant difference in the volume between the two groups (all P>0.05). At 3 months, the RFA group had a larger VRRs than that in the MWA group (62.08%±12.46% vs. 46.90%±23.16%, t=-2.45, P=0.021). However, at 1 and 6 months, no statistical significance was observed (both P>0.05). No significant difference was observed in the effective rates at the last follow-up (14/18 vs. 18/18, P=0.104). However, the RFA group had a lower cosmetic score than that in the MWA group (1.78±0.43 vs. 2.17±0.51, t=-2.47, P=0.019). There was no statistically significant difference in the complication rates between the two groups (all P>0.05). Conclusions: Both MWA and RFA were effective and safe treatments for BTNs, with no significant differences in short-term efficacy and safety. In addition, the RFA group showed slightly more favorable outcomes than the MWA group in terms of cosmetic improvement.

Reentrance of interface superconductivity in a high-Tc cuprate heterostructure

Increasing the carrier density in a Mott insulator by chemical doping gives rise to a generic superconducting dome in high temperature superconductors. An intriguing question is whether a second superconducting dome may exist at higher dopings. Here we heavily overdope La2-xSrxCuO4 (0.45 ≤ x ≤ 1.0) and discover an unprecedented reentrance of interface superconductivity in La2-xSrxCuO4 /La2CuO4 heterostructures. As x increases, the superconductivity is weakened and completely fades away at x = 0.8; but it revives at higher doping and fully recovers at x = 1.0. This is shown to be correlated with the suppression of the interfacial charge transfer around x = 0.8 and the weak-to-strong localization crossover in the La2-xSrxCuO4 layer. We further construct a theoretical model to account for the sophisticated relation between charge localization and interfacial charge transfer. Our work advances both the search for and control of new superconducting heterostructures.

[Effects of cinepazide maleate injection on blood pressure in patients with acute ischemic stroke and hypertension]

Objective: To investigate the blood pressure change in patients with acute ischemic stroke (AIS) and hypertension treated with cinepazide maleate injection. Methods: This was a subgroup analysis of post-marketing clinical confirmation study of cinepazide maleate injection for acute ischemic stroke: a randomized, double-blinded, multicenter, placebo-parallel controlled trial, which conducted in China from August 2016 to February 2019. Eligible patients fulfilled the inclusive criteria of acute anterior circulation ischemic stroke with National Institutes of Health Stroke Scale (NIHSS) scores of 7-25. The primary endpoints were mean blood pressure of AIS patients treated with cinepazide maleate or control, which were assessed during the treatment period (14 days), and the proportion of the patients with normal blood pressure was analyzed after the treatment period. Furthermore, a subgroup analysis was performed to investigate a possible effect of the history of hypertension on outcomes. Results: This analysis included 809 patients with hypertension. There was no significant difference in patients blood pressure and the proportion of patients with normal blood pressure (60.5% vs. 59.0%,P>0.05) between cinepazide maleate group and control group. Conclusion: Administration of cinepazide maleate injection does not affect the management of clinical blood pressure in patients with AIS.

Pressure-Induced Superconductivity up to 9 K in the Quasi-One-Dimensional KMn_{6}Bi_{5}

The Mn-based superconductor is rare owing to the strong magnetic pair-breaking effect. Here we report on the discovery of pressure-induced superconductivity in KMn_{6}Bi_{5}, which becomes the first ternary Mn-based superconductor. At ambient pressure, the quasi-one-dimensional KMn_{6}Bi_{5} is an antiferromagnetic metal with T_{N}≈75  K. By measuring resistance and ac magnetic susceptibility under hydrostatic pressures up to 14.2 GPa in a cubic anvil cell apparatus, we find that its antiferromagnetic transition can be suppressed completely at a critical pressure of P_{c}≈13  GPa, around which bulk superconductivity emerges and displays a superconducting dome with the maximal T_{c}^{onset}=9.3  K achieved at about 14 GPa. The close proximity of superconductivity to a magnetic instability in the temperature-pressure phase diagram of KMn_{6}Bi_{5} and an unusually large μ_{0}H_{c2}(0) exceeding the Pauli paramagnetic limit suggests an unconventional magnetism-mediated paring mechanism. In contrast to the binary MnP, the flexibility of the crystal structure and chemical compositions in the ternary AMn_{6}Bi_{5} (A=alkali metal) can open a new avenue for finding more Mn-based superconductors.

Direct Observation of Coherent Longitudinal and Shear Acoustic Phonons in TaAs Using Ultrafast X-Ray Diffraction

Using femtosecond time-resolved x-ray diffraction, we investigated optically excited coherent acoustic phonons in the Weyl semimetal TaAs. The low symmetry of the (112) surface probed in our experiment enables the simultaneous excitation of longitudinal and shear acoustic modes, whose dispersion closely matches our simulations. We observed an asymmetry in the spectral line shape of the longitudinal mode that is notably absent from the shear mode, suggesting a time-dependent frequency chirp that is likely driven by photoinduced carrier diffusion. We argue on the basis of symmetry that these acoustic deformations can transiently alter the electronic structure near the Weyl points and support this with model calculations. Our study underscores the benefit of using off-axis crystal orientations when optically exciting acoustic deformations in topological semimetals, allowing one to transiently change their crystal and electronic structures.

Photocurrent-driven transient symmetry breaking in the Weyl semimetal TaAs

Symmetry plays a central role in conventional and topological phases of matter, making the ability to optically drive symmetry changes a critical step in developing future technologies that rely on such control. Topological materials, like topological semimetals, are particularly sensitive to a breaking or restoring of time-reversal and crystalline symmetries, which affect both bulk and surface electronic states. While previous studies have focused on controlling symmetry via coupling to the crystal lattice, we demonstrate here an all-electronic mechanism based on photocurrent generation. Using second harmonic generation spectroscopy as a sensitive probe of symmetry changes, we observe an ultrafast breaking of time-reversal and spatial symmetries following femtosecond optical excitation in the prototypical type-I Weyl semimetal TaAs. Our results show that optically driven photocurrents can be tailored to explicitly break electronic symmetry in a generic fashion, opening up the possibility of driving phase transitions between symmetry-protected states on ultrafast timescales.

[Effectiveness and safety of ultrasound-guided microwave ablation for the treatment of primary hyperparathyroidism in 12 patients with parathyroid adenoma]

To investigate the effectiveness and safety of ultrasound-guided microwave ablation (MWA) in treatment of primary hyperparathyroidism (PHPT). A total of 12 PHPT patients with parathyroid adenoma were treated with MWA in Nanjing University of Chinese Medicine Affiliated Hospital of Integrated Traditional Chinese and Western Medicine from May 2019 to February 2021. The patients were followed up once every 3 months for 3-12 months. Levels of serum parathyroid hormone (PTH), calcium and phosphorus were detected before and 20 min, 4h and 1day after ablation, and during follow-up period. The volume and volume reduction rate of parathyroid lesion were compared before the treatment and at the end of follow-up. The technical and clinical success of MWA were assessed as well. At the end of follow-up, median serum PTH [66.60 (42.21,80.03) ng/L vs.169.90 (89.01,396.50) ng/L] and calcium [2.39 (2.32,2.49) mmol/L vs. 2.75 (2.57,2.96) mmol/L] levels in 12 patients decreased significantly (all P<0.05). A complete response in terms of PTH and calcium levels was achieved in 6 of the 12 patients, while 4 of the patients had slightly elevated PTH levels just above the upper limit of normal reference range, and 2 of the patients remained abnormal PTH and calcium levels. The clinical cure rate was 50%. The volumes of all lesion after ablation were significantly decreased (P<0.05), with the technical success rate reaching 92.3%. No serious complications were observed. Ultrasound-guided MWA, thus, is safe and effective in the treatment of PHPT.

[Trend analysis and prediction of colorectal cancer morbidity and mortality of residents in urban areas of Guangzhou from 1972 to 2015]

Objective: To analyze the trend of mortality and incidence of colorectal cancer among urban residents in Guangzhou from 1972 to 2015 and to predict the mortality of colorectal cancer from 2016 to 2025. Methods: The mortality data of colorectal cancer among urban residents in Guangzhou were collected from the death registration of malignant tumors of Guangzhou Health Statistics Bureau (1972-1979), Guangzhou Health Statistics (1980-2001), Guangzhou Cancer Registration Annual Report (2002-2009) and China Cancer Registration Annual Report (2010-2015). The incidence of colorectal cancer was collected from Guangzhou Cancer Registration Annual Report (2002-2009) and China Cancer Registration Annual Report (2010-2015). The incidence and mortality data of colorectal cancer coded as C18-C21 in 10th Edition of International Classification of Diseases (ICD-10) were obtained from the above data, and the demographic data were from the Guangzhou Municipal Bureau of Statistics. Joinpoint model was used to calculate the annual change percentage (APC) and average annual change percentage (AAPC) of colorectal cancer mortality and incidence among urban residents in Guangzhou from 1972 to 2015 and from 2002 to 2015. ARIMA model was used to predict colorectal cancer mortality from 2016 to 2025. Results: There were 19 309 colorectal cancer deaths among urban residents in Guangzhou from 1972 to 2015. The crude mortality rate of colorectal cancer increased from 4.33/100 000 to 24.89/100 000 (AAPC=4.2%, P<0.001). A total of 24 033 new cases of colorectal cancer were reported in Guangzhou from 2002 to 2015. The crude incidence rate of colorectal cancer increased from 22.95/100 000 to 52.81/100 000 (AAPC=6.6%, P<0.001). The mortality rate of colorectal cancer among urban residents of Guangzhou would continuously increase from 2016 to 2025 and reach 29.53/100 000 in 2025. Conclusion: The mortality rate of colorectal cancer among urban residents of Guangzhou from 1972 to 2015 and the incidence rate of colorectal cancer from 2002 to 2015 both show an upward trend. The mortality rate will increase from 2016 to 2025.

Unconventional Hall response in the quantum limit of HfTe5

Interacting electrons confined to their lowest Landau level in a high magnetic field can form a variety of correlated states, some of which manifest themselves in a Hall effect. Although such states have been predicted to occur in three-dimensional semimetals, a corresponding Hall response has not yet been experimentally observed. Here, we report the observation of an unconventional Hall response in the quantum limit of the bulk semimetal HfTe5, adjacent to the three-dimensional quantum Hall effect of a single electron band at low magnetic fields. The additional plateau-like feature in the Hall conductivity of the lowest Landau level is accompanied by a Shubnikov-de Haas minimum in the longitudinal electrical resistivity and its magnitude relates as 3/5 to the height of the last plateau of the three-dimensional quantum Hall effect. Our findings are consistent with strong electron-electron interactions, stabilizing an unconventional variant of the Hall effect in a three-dimensional material in the quantum limit.

Tracking Ultrafast Photocurrents in the Weyl Semimetal TaAs Using THz Emission Spectroscopy

We investigate polarization-dependent ultrafast photocurrents in the Weyl semimetal TaAs using terahertz (THz) emission spectroscopy. Our results reveal that highly directional, transient photocurrents are generated along the noncentrosymmetric c axis regardless of incident light polarization, while helicity-dependent photocurrents are excited within the ab plane. This is consistent with earlier static photocurrent experiments, and demonstrates on the basis of both the physical constraints imposed by symmetry and the temporal dynamics intrinsic to current generation and decay that optically induced photocurrents in TaAs are inherent to the underlying crystal symmetry of the transition metal monopnictide family of Weyl semimetals.

[Qualitative pathological assessment of liver fibrosis regression after antiviral therapy in patients with chronic hepatitis B]

Objective: To investigate the methods for qualitative pathological assessment of dynamic changes in liver fibrosis/cirrhosis after antiviral therapy in patients with chronic hepatitis B (CHB), since antiviral therapy can partially reverse liver fibrosis and cirrhosis caused by hepatitis B and semi-quantitative, rather than qualitative, pathological assessment is often used for the research on liver fibrosis regression. Methods: Previously untreated CHB patients with liver fibrosis and cirrhosis were enrolled, and liver biopsy was performed before treatment and at 78 weeks after the antiviral therapy based on entecavir. The follow-up assessment was performed once every half a year. Based on the proportion of different types of fibrous septum, we put forward the new qualitative criteria called P-I-R classification (predominantly progressive, predominantly regressive, and indeterminate) for evaluating dynamic changes in liver fibrosis. This classification or Ishak fibrosis stage was used to evaluate the change in liver fibrosis after treatment and Ishak liver inflammation score was used to evaluate the change in liver inflammation after treatment. Results: A total of 112 CHB patients who underwent liver biopsy before and after treatment were enrolled, and among these patients, 71 with an Ishak stage of ≥3 and qualified results of live biopsy were included in the final analysis. Based on the P-I-R classification, 58% (41/71) were classified as predominantly progressive, 29% (21/71) were classified as indeterminate, and 13% (9/71) were classified as predominantly regressive; there were no significant differences between the three groups in alanine aminotransferase, aspartate aminotransferase, albumin, HBeAg positive rate, HBV DNA, and liver stiffness (P < 0.05). After treatment, the proportion of predominantly progressive, indeterminate, or predominantly regressive patients changed to 11% (8/71), 11% (8/71), and 78% (55/71), respectively. Among the 35 patients who had no change in Ishak stage after treatment, 72% (25/35) were classified as predominantly regressive and had certain reductions in the Laennec score, percentage of collagen area, and liver stiffness. Conclusion: This new P-I-R classification can be used to assess the dynamic changes in liver fibrosis after antiviral therapy in CHB patients.

Temperature-Driven Topological Phase Transition and Intermediate Dirac Semimetal Phase in ZrTe_{5}

We present an infrared spectroscopy study of ZrTe_{5}, which confirms a recent theoretical proposal that this material exhibits a temperature-driven topological quantum phase transition from a weak to a strong topological insulating state with an intermediate Dirac semimetal state around T_{p}≃138  K. Our study details the temperature evolution of the energy gap in the bulk electronic structure. We found that the energy gap closes around T_{p}, where the optical response exhibits characteristic signatures of a Dirac semimetal state, i.e., a linear frequency-dependent optical conductivity extrapolating to the origin (after subtracting a weak Drude response). This finding allows us to reconcile previous diverging reports about the topological nature of ZrTe_{5} in terms of a variation of T_{p} that depends on the crystal growth condition.

[Association between SCN1A rs3812718 polymorphism and generalized epilepsy with febrile seizures plus]

OBJECTIVE

To investigate the association between SCN1A rs3812718 polymorphism and generalized epilepsy with febrile seizures plus (GEFS+), and to provide potential molecular targets for the diagnosis and treatment of GEFS+.

METHODS

The iPLEX technique in the MassARRAY system was used to determine SCN1A rs3812718 polymorphism, genotype frequency, and allele frequency in 50 patients with GEFS+ and 50 healthy controls.

RESULTS

As for the frequencies of CC, CT, and TT genotypes in SCN1A rs3812718, there was a significant difference in the frequency of TT genotype between the GEFS+ group and the control group (P<0.05). There was also a significant difference in the frequency of T allele between the two groups (P<0.05). Compared with those carrying CC genotype or C allele, the individuals with CT genotype , TT genotype or T allele had a higher risk of developing GEFS+ (CT/CC: OR=4.05, 95%CI: 1.04-15.69; TT/CC: OR=30.60, 95%CI: 6.46-144.85; T/C: OR=4.64, 95%CI: 2.54-8.48).

CONCLUSIONS

SCN1A rs3812718 polymorphism is a risk factor for GEFS+, and the population carrying T allele may have an increased risk of GEFS.

[Correlation of liver stiffness measured by FibroTouch and FibroScan with Ishak fibrosis score in patients with chronic hepatitis B]

Objective: To investigate the correlation of liver stiffness measured by FibroTouch (FT) and FibroScan (FS) with Ishak fibrosis score in patients with chronic hepatitis B. Methods: A total of 313 patients with chronic hepatitis B who visited Department of Liver Cirrhosis in Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine from November 2014 to May 2016 were enrolled. All the patients underwent liver biopsy, and FT and FS were used to determine liver stiffness measurement (LSM). Serum biochemical parameters were measured, and the aspartate aminotransferase-to-platelet ratio index (APRI) in a multi-parameter model of liver fibrosis and fibrosis-4 (FIB-4) index were calculated. The consistency between the results of four noninvasive examinations and Ishak fibrosis score was compared. The t-test was used for comparison of LSM determined by FT and FS. Pearson correlation analysis was used investigate the correlation between LSM determined by FT and FS; Spearman correlation analysis was used to investigate the correlation of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and Knodell score with LSM determined by FT and FS; the correlation between LSM determined by FT and FS and fibrosis stage was analyzed by partial correlation analysis adjusted by Knodell score for liver inflammatory activity; Spearman correlation analysis was used for APRI, FIB-4, and fibrosis stage. Based on the Ishak fibrosis score, the receiver operating characteristic (ROC) curve was used to analyze the values of four noninvasive methods in the diagnosis of liver fibrosis. Results: There was no significant difference in LSM measured by FT and FS in all patients (15.75±9.42 kPa vs 15.42±10.52 kPa, P > 0.05) and Pearson correlation analysis indicated a significant positive correlation between them (r = 0.858, P < 0.01); serum ALT and AST levels and liver inflammatory activity were correlated with LSM determined by FT and FS. There was a significant positive correlation between LSM determined by FT and FS and fibrosis stage (r = 0.501 and 0.526, both P < 0.001), and APRI and FIB-4 were also positively correlated with fibrosis stage (r = 0.236 and 0.218, both P < 0.001). Based on the Ishak fibrosis score, in the diagnosis of fibrosis stages F3, F4, F5, and F6, the areas under the ROC curve were 0.915/0.856/0.839/0.816 for FT, 0.933/0.883/0.849/0.856 for FS, 0.618/0.630/0.608/0.638 for APRI, and 0.614/0.624/0.595/0.649 for FIB-4, and FT and FS had a significantly larger areas under the ROC curve than APRI and FIB-4. Conclusion: LSM determined by FT or FS has a good correlation with the Ishak fibrosis score, so FT and FS have a significantly better diagnostic performance for liver fibrosis than APRI and FIB-4.

[Mechanism of Astragaloside prevents cholestatic liver fibrosis through inhibition of Notch signaling activation]

Objective: The Notch signaling pathway is closely related to biliary fibrosis. Previous studies have shown that Astragaloside (AS) can prevent the progression of cholestatic liver fibrosis. The purpose of this study is to observe the effect of AS on the regulation of Notch signaling pathway in biliary fibrosis. Methods: Cholestatic liver fibrosis was established by common bile duct ligation (BDL) in rats. Two weeks after BDL, the rats were randomly divided into a model group (i.e., BDL), an Astragalosides group (AS), and a sorafenib (SORA) positive control group and treated for 3 weeks. Bile duct proliferation and liver fibrosis were determined by tissue staining. Protein and gene expression were determined by immunostaining, immunoblotting and RT-PCR, respectively. Activation of the Notch signaling pathway was evaluated by analyzing expressions of Notch-1, -2, -3, -4, Jagged (JAG)1, Delta like (DLL)-1, -3, -4, Hes1, Numb and RBP-Jκ. Statistical analysis of variance analysis, q test, P < 0.05 showed that the difference was statistically significant. Results: (1) AS significantly reduced the deposition of collagen and the Hyp content of liver tissue (500.15 ± 86.10 vs. 625.72 ± 105.62, P = 0.031), and inhibited the activation of hepatic stellate cells. (2) AS significantly decreased the protein and mRNA expressions of transforming growth factor (TGF)-β1 (1.02±0.15 vs. 1.89±0.36, P = 0.007; 1.17±0.18 vs. 1.68±0.29, P = 0.013, respectively) and α-smooth muscle actin (α-SMA, 0.41±0.11 vs. 0.72±0.16, P = 0.003; 1.71±0.57 vs. 2.68±0.46, P = 0.008, respectively) compared with BDL group. In contrast, AS significantly enhanced expression of the Smad 7 protein compared with the BDL group (0.72±0.008 vs. 0.33±0.001, P = 0.005). AS also reduced biliary epithelial cell proliferation. AS reduced the mRNA levels of CK7, CK8 and CK18 (1.31±0.39 vs. 2.63±0.82, P = 0.009; 0.71±0.09 vs. 0.87±0.08, P = 0.031; 2.56±0.32 vs. 3.41±0.39, P = 0.010, respectively) and reduced the positive areas of CK19 and OV6 (62 337.17±21 873.38 vs. 22 5472.67±26 933.63, P = 0.000; 92 237.43±15 894.11 vs. 171 298.13±61 761.37, P = 0.000, respectively). (3) The mRNA expression of Notch-2, -3, -4 and JAG1 were significantly reduced in the AS group compared to the BDL group (1.07±0.19 vs. 1.51±0.28, P = 0.044; 0.99±0.24 vs. 1.18±0.10, P = 0.043; 1.36±0.42 vs. 3.40±0.44, P = 0.048; 2.62±0.43 vs. 3.73±0.83, P = 0.046, respectively). In contrast, the mRNA level of Numb was clearly enhanced after AS treatment (0.90±0.05 vs. 0.75±0.11, P = 0.019). In addition, consistent with the mRNA levels, the protein expressions of Notch-2, -3, -4 and JAG1 were reduced significantly (1.27±0.18 vs. 1.71±0.26, P = 0.004; 0.99±0.11 vs. 4.38±0.60, P = 0.001; 1.76±0.32 vs. 4.01±0.74, P = 0.002; 1.62±0.33 vs. 2.74±0.63, P = 0.002) and the Numb protein level was increased significantly (1.50±0.15 vs. 0.85±0.11, P = 0.001) in AS group compared with BDL group. Conclusion: AS may prevent cholestatic liver fibrosis via inhibition of the Notch signaling pathway, thereby inhibiting the abnormal proliferation of biliary epithelial cells. Results indicate that AS may be a potential treatment for cholestatic liver disease.

Magnetic and transport properties of a layered compound Ce2Te5

Ce₂Te₅ single crystals were successfully grown using RbCl/LiCl flux method. The structure of Ce₂Te₅ can be viewed as a combination of CeTe₂ and CeTe₃. The experimental results of magnetic susceptibility [Formula: see text], isothermal magnetization M(H), electrical resistivity [Formula: see text], and heat capacity C(T) show two clear anomalies at 5.1 and 2.3 K, which correspond to a ferrimagnetic and a possible antiferromagnetic transition, respectively. Both of [Formula: see text] and C(T) confirm a third transition at 0.9 K. The resistivity shows a huge anisotropy with the current applied in [Formula: see text] and [Formula: see text] directions. Our experimental results prefer the scenario that the three consecutive transitions in Ce₂Te₅ are attributed to two different kinds of origin, which are independent and responsible for the magnetic orders observed in CeTe₂ and CeTe₃.

Temperature-tunable Fano resonance induced by strong coupling between Weyl fermions and phonons in TaAs

Strong coupling between discrete phonon and continuous electron–hole pair excitations can induce a pronounced asymmetry in the phonon line shape, known as the Fano resonance. This effect has been observed in various systems. Here we reveal explicit evidence for strong coupling between an infrared-active phonon and electronic transitions near the Weyl points through the observation of a Fano resonance in the Weyl semimetal TaAs. The resulting asymmetry in the phonon line shape, conspicuous at low temperatures, diminishes continuously with increasing temperature. This behaviour originates from the suppression of electronic transitions near the Weyl points due to the decreasing occupation of electronic states below the Fermi level (E_F) with increasing temperature, as well as Pauli blocking caused by thermally excited electrons above E_F. Our findings not only elucidate the mechanism governing the tunable Fano resonance but also open a route for exploring exotic physical phenomena through phonon properties in Weyl semimetals.

The study of lattice vibrations coupled to electronic excitations may provide an avenue for exploring exotic physical phenomena. Here, Xu et al. observe a Fano resonance in the Weyl semimetal TaAs, revealing evidence for a strong coupling between phonons and Weyl fermions.

Superconductivity in HfTe5 across weak to strong topological insulator transition induced via pressures

Recently, theoretical studies show that layered HfTe₅ is at the boundary of weak & strong topological insulator (TI) and might crossover to a Dirac semimetal state by changing lattice parameters. The topological properties of 3D stacked HfTe₅ are expected hence to be sensitive to pressures tuning. Here, we report pressure induced phase evolution in both electronic & crystal structures for HfTe₅ with a culmination of pressure induced superconductivity. Our experiments indicated that the temperature for anomaly resistance peak (Tp) due to Lifshitz transition decreases first before climbs up to a maximum with pressure while the Tp minimum corresponds to the transition from a weak TI to strong TI. The HfTe₅ crystal becomes superconductive above ~5.5 GPa where the Tp reaches maximum. The highest superconducting transition temperature (Tc) around 5 K was achieved at 20 GPa. Crystal structure studies indicate that HfTe₅ transforms from a Cmcm phase across a monoclinic C2/m phase then to a P-1 phase with increasing pressure. Based on transport, structure studies a comprehensive phase diagram of HfTe₅ is constructed as function of pressure. The work provides valuable experimental insights into the evolution on how to proceed from a weak TI precursor across a strong TI to superconductors.

[Retrospective study on the efficacy of different chemotherapy regimens concurrently combined with intensity modulated radiation therapyin treatment of Ⅲ-Ⅳa stage nasopharyngeal carcinoma]

Objective:To compare the near and long term efficacy and safety of paclitaxel(TAX) plus cisplatin(DDP) (TP regimen) and DDP plus 5-FU(PF regimen) concurrently combined with IMRT in treatment of patients with advanced NPC.Method: A retrospective analysis on 108 advanced NPC cases from January 2010 to December 2012 was conducted. The patients were divided into TP group(57 cases) and PF group(51 cases) according to therapy regimen. TP group received IMRT combined with TP therapy, and PF group received IMRT combined with PF regimen, two groups were both used 4 cycles of chemotherapy, toxicity reactions during concurrent radiochemotherapy were noted. Two months after treatment, near clinical efficacies of the two groups were determined, and then, a three years followingup was conducted, during which recurrence ratio, metastasis ratio, local control ratio and survival rate were analyzed. Result: Two months after treatment, the total effective ratio of TP group(84.2% vs.76.5%) was higher than PF group,however, the difference was not statistically significant(P>0.05). Gastrointestinal reaction(70.2% vs.66.7%), marrow inhibition(75.4% vs.82.4%), liver function damage(12.3% vs.13.7%), radioactive oral and pharyngeal injury(91.2% vs.98.0%)， hearing damage(15.8% vs.15.7%) in the two groups during chemoradiotherapy had no significant differences(P>0.05). During followingup, the recurrence and metastasis ratio in TP group(33.3% vs.47.1%) was lower than PF group(χ²=2.116,P=0.146). TP group with The local control rate(73.7% vs.68.5%) and survival rate(84.2% vs.78.4%) after three years treatment in TP group were higher than PF group(χ²=0.336,P=0.562；χ²=0.596,P=0.440). Conclusion: IMRT concurrently combined with TP and PF respectively are both effective methods for treatment of advanced NPC. In this study, IMPT plus TP concurrent chemoradiotherapy has a certain superiority in near and long term clinical treatment efficacy and safety.

[Relationship between serum erythropoietin levels and brain injury in preterm infants]

OBJECTIVE

To study the relationship between the levels of erythropoietin (EPO) in serum and brain injury in preterm infants.

METHODS

Three hundred and four preterm infants (gestational age: 28-34 weeks) born between October 2014 and September 2015 were enrolled in this study. Brain injury was diagnosed using cerebral ultrasound and MRI. The levels of EPO, S100 protein, neuron-specific enolase (NSE) and myelin basic protein (MBP) in serum were detected using ELISA. To compare the incidence of brain injury in different serum EPO levels in preterm infants, and the relationship between brain injury and serum EPO levels was analyzed.

RESULTS

The incidence rate of brain injury in preterm infants was 41.1% (125/304). The incidence rate of brain injury in the low EPO level group was significantly higher than that in the middle-high EPO level groups (P<0.01). The serum levels of S100 protein, NSE, and MBP in the brain injury groups were significantly higher than in the control group (P<0.01). The serum EPO levels were negatively correlated with serum S100 protein concentration and NSE levels (P<0.05). According to the multiple logistic regression analysis, low gestational age, low birth weight, asphyxia, prolonged mechanical ventilation, anemia and low serum EPO levels were the risk factor for brain injury in preterm infants.

CONCLUSIONS

There is a higher incidence rate of brain injury in preterm infants with lower serum EPO levels. The serum EPO levels may be correlated with brain injury in preterm infants.

[Relationship between serum erythropoietin levels and brain injury in preterm infants]

OBJECTIVE

To study the relationship between the levels of erythropoietin (EPO) in serum and brain injury in preterm infants.

METHODS

Three hundred and four preterm infants (gestational age: 28-34 weeks) born between October 2014 and September 2015 were enrolled in this study. Brain injury was diagnosed using cerebral ultrasound and MRI. The levels of EPO, S100 protein, neuron-specific enolase (NSE) and myelin basic protein (MBP) in serum were detected using ELISA. To compare the incidence of brain injury in different serum EPO levels in preterm infants, and the relationship between brain injury and serum EPO levels was analyzed.

RESULTS

The incidence rate of brain injury in preterm infants was 41.1% (125/304). The incidence rate of brain injury in the low EPO level group was significantly higher than that in the middle-high EPO level groups (P<0.01). The serum levels of S100 protein, NSE, and MBP in the brain injury groups were significantly higher than in the control group (P<0.01). The serum EPO levels were negatively correlated with serum S100 protein concentration and NSE levels (P<0.05). According to the multiple logistic regression analysis, low gestational age, low birth weight, asphyxia, prolonged mechanical ventilation, anemia and low serum EPO levels were the risk factor for brain injury in preterm infants.

CONCLUSIONS

There is a higher incidence rate of brain injury in preterm infants with lower serum EPO levels. The serum EPO levels may be correlated with brain injury in preterm infants.

Observation of Fermi-Arc Spin Texture in TaAs

We have investigated the spin texture of surface Fermi arcs in the recently discovered Weyl semimetal TaAs using spin- and angle-resolved photoemission spectroscopy. The experimental results demonstrate that the Fermi arcs are spin polarized. The measured spin texture fulfills the requirement of mirror and time-reversal symmetries and is well reproduced by our first-principles calculations, which gives strong evidence for the topologically nontrivial Weyl semimetal state in TaAs. The consistency between the experimental and calculated results further confirms the distribution of chirality of the Weyl nodes determined by first-principles calculations.

Gradual-order enhanced stability: a frozen section of electrospun nanofibers for energy storage

A combination of electrospinning and a frozen section has been used to gradually lower the scale of the active materials, thus effectively avoiding nano-reunion, to a certain extent, during electrode fabrication. The as-fabricated electrode-based supercapacitor possesses high electrochemical capacitance and good stability. Our results demonstrate a universal top-down route for the controllable fabrication of homodisperse nanoparticle electrodes for use in high performance electrochemical devices.

EFFICACY OF DIFFERENT RESECTIONS ON NON-MUSCLE-INVASIVE BLADDER CANCER AND ANALYSIS OF THE OPTIMAL SURGICAL METHOD

This study aimed to analyze the clinical efficacy of different resections in treating non-muscle-invasive bladder cancer (NMIBC), including partial cystectomy, transurethral resection of bladder tumor (TURBT) and holmium laser resection of bladder tumor. Two hundred and sixteen patients were recruited with NMIBC who were available for follow-up visits in hospital, including 62 cases treated with partial cystectomy, 90 cases treated with TURBT and 64 cases with holmium laser resection. Analysis was made on the cases with tumor relapse in the two years, on operation time, blood loss, time for indwelling urinary catheter, hospital stay and complications after operation. Results were compared to the clinical efficacy of these operation patterns. It was found that the two-year relapse rate for TURBT group, partial cystectomy group and Holmium laser resection group was 41%, 31%, and 33% respectively, and the difference had no statistical significance (p>0.05). Both the TURBT group and holmium laser resection group had shorter operation time, hospital stay and time for indwelling urinary catheter as well as much less blood loss when compared with the partial cystectomy group; the difference had statistical significance (p<0.001). In terms of complications, the TURBT group was likely to induce obturator nerve reflex and bladder perforation while the partial cystectomy group was likely to induce bladder spasm. Therefore, this study presumes that holmium laser resection and TURBT are much safer and quicker for recovery and obviously superior to the partial cystectomy.

Value of alpha-fetoprotein and clinical characteristics in patients with liver neoplasm

This article aimed to investigate the value of α-fetoprotein (AFP) for the diagnosis of hepatocellular carcinoma (HCC) and to evaluate the relationship between AFP and various clinical variables of HCC comprehensively. A retrospective study of postoperative patients diagnosed with liver neoplasm from two Chinese centers was enrolled in our study.A total of 3050 patients were included. The best cut-off point of AFP for the diagnosis of HCC was 20ng/ml with ideal sensitivity (69.74%), specificity (91.18%), LR (4.12) and YI (0.61). Non-HBV infection patients showed the highest specificity (94.44%) but lowest sensitivity (60.13%). In HBV infection. Patients, HBsAg, HBeAb, and HBcAb positive patients had the highest sensitivity (79.55%) and specificity (58.49%). AFP levels increased significantly in symptomatic patients (p=0.011). Those patients with tumor sizes ≥10cm had much higher serum AFP level compared with smaller tumors ones (p=0.014). AFP levels increased remarkably in patients with vascular invasion (p=0.015). Stepwise logistic regression showed tumor size (≥10cm) was an independent predictor of elevated AFP (OR=2.743, 95%CI: 1.167-6.447, P=0.021). The best discriminating AFP value for the diagnosis of HCC is 20ng/ml; HBsAg, HBeAb and HBcAb positive patients have the optimal sensitivity and specificity; tumor size ≥ 10cm is an independent predictor of elevated AFP.

[Early multi-disciplinary intervention reduces neurological disability in premature infants]

OBJECTIVE

This study aimed to evaluate the effectiveness of multi-disciplinary treatment approaches in reducing neurological disabilities in premature infants.

METHODS

A total of 117 infants who were born premature in our hospital between March 2008 and February 2010 but had no congenital malformations and no severe neonatal complications, were enrolled in this study. They were randomly allocated to a multi-disciplinary treatment group (n=63) and a control group (n=54). While patients in the control group underwent an early conventional treatment, those in the multi-disciplinary treatment group were subjected to regular development monitoring, neurological examination and screening for brain injury, neuro-nutrition and neurodevelopment therapies, and rehabilitation training.

RESULTS

The incidence rates of abnormalities in posture, reflex, sleep, muscle tone and EEG were significantly lower in the multi-disciplinary treatment group than in the control froup (P<0.05) at corrected postnatal ages of 6-12 months. At corrected postnatal ages of 6, 12, 18 and 24 months, both mental development index (MDI) and psychomotor development index (PDI) scores were significantly higher in the multi-disciplinary treatment group than in the control group (P<0.05). At corrected postnatal age of 3 years, incidence rates of cerebral palsy, language barrier, abnormal muscle tone and hearing impairment were significantly lower in the multi-disciplinary treatment group than in the control group (P<0.05).

CONCLUSIONS

Early multi-disciplinary intervention approaches may significantly improve mental and motor developments and reduce the incidence of cerebral palsy-associated neurological disabilities in premature infants.

Medial arcuate ligament: a new anatomic landmark facilitates the location of the renal artery in retroperitoneal laparoscopic renal surgery

PURPOSE

The purpose of this study was to introduce a new method for locating the renal artery during retroperitoneal laparoscopic renal surgery.

PATIENTS AND METHODS

The medial arcuate ligament (MAL) is a tendinous arch in the fascia under the diaphragm that arches across the psoas major muscle and is attached medially to the side of the first or the second lumbar vertebra. The renal artery arises at the level of the intervertebral disc between the L1 and L2 vertebrae. We evaluate the role of the MAL that serves as an anatomic landmark for locating the renal artery during retroperitoneal laparoscopic renal surgery.

RESULTS

There is a reproducible consistent anatomic relationship between MAL and the renal artery in 210 cases of retroperitoneal laparoscopic renal surgery. Two main types of the MAL, the "narrow arch" and the "fascial band" types, can be observed.

CONCLUSION

MAL can serve as an accurate and reproducible anatomic landmark for the identification of the renal artery during retroperitoneal laparoscopic renal surgery.

Fabrication and characterization of n-ZnO nanonails array/p(+)-GaN heterojunction diode

A novel heterojunctional structure of n-ZnO nanonails array/p(+)-GaN light-emitting diode was fabricated by Chemical Vapor Deposition method. A broad electroluminescence spectrum shows two peaks centered at 435 nm and 478 nm at room temperature, respectively. By comparing the photoluminescence and electroluminescence spectra, together with analyzing the energy band structure of heterojunction light emitting diode, it suggested that the electroluminescence peak located at 435 nm originates from Mg acceptor level of p(+)-GaN layer, whereas the electroluminescence peak located at 478 nm originates from the defects of n-ZnO nanonails array.

High energy pseudogap and its evolution with doping in Fe-based superconductors as revealed by optical spectroscopy

We report optical spectroscopic measurements on electron- and hole-doped BaFe2As2. We show that the compounds in the normal state are not simple metals. The optical conductivity spectra contain, in addition to the free carrier response at low frequency, a temperature-dependent gap-like suppression at fairly high energy scale near 0.6 eV. This suppression evolves with the As–Fe–As bond angle induced by electron or hole doping. Furthermore, the feature becomes much weaker in the Fe-chalcogenide compounds. We elaborate that the feature is mainly caused by the strong Hund's rule coupling effect between the itinerant electrons and localized electron moment arising from the multiple Fe 3d orbitals. The coupling strength changes with the environment of the Fe atom. Our experiments demonstrate the coexistence of itinerant and localized electrons in iron-based compounds, which would then lead to a more comprehensive picture of the metallic magnetism in the materials.

Oncological and functional results of extraperitoneal laparoscopic radical prostatectomy

The oncological and functional results of 329 cases in a population treated with extraperitoneal laparoscopic radical prostatectomy (ELRP) were evaluated retrospectively. A total of 329 inconsecutive patients with prostate cancer (PCa) who underwent ELRP were retrospectively analyzed. The median initial prostate-specific antigen (PSA) level was 17.35 ng/ml. The median biopsy Gleason score was 7.77. Patients with a T2 or T3a clinical stage had received preoperative neoadjuvant hormonal therapy (NHT) for 3 to 9 months prior to ELRP. No conversion or re-intervention were observed. The median time for anastomosis, surgery time and postoperative catheterization time were 13.0 min, 90.0 min and 6 days, respectively. The median estimated blood loss was 75 ml. There were 12 temporary urinary leakages requiring prolonged catheterization to 14 days. There was 1 case of deep vein thrombosis, 1 case of alimentary tract hemorrhage and 7 cases of anterior urethral stricture. The median follow-up time was 27 months. A total of 17 patients were lost during the follow-up period. No rectal injury, lymphocele, incision hernia, postoperative persistent urinary leak or anastomotic stricture occurred. Younger patients (≤67 years of age) had a more rapid recovery of continence and a better postoperative potency. The overall positive surgical margin rate was 16.7%, which correlated with the pathological stage and Gleason score, respectively (both P<0.001). A total of 89 (28.6%) patients were diagnosed with biochemical recurrence. The initial PSA value, PSM, pathological stage and Gleason score were identified as independent prognostic factors for biochemical recurrence-free survival using multivariate analysis. Our results demonstrated that preoperative NHT had significant effects on the pathological Gleason score (P<0.001) and surgical margin (P=0.027), but no significant impact on biochemical recurrence (P=0.202). The reproducibility of ELRP has been proven as a reliable curative treatment in Western countries during the last 15 years. Due to the increase in PCa patients, the results of our study may aid surgeons who use ELRP for the first time.

Superconductivity above 30 K in alkali-metal-doped hydrocarbon

The recent discovery of superconductivity with a transition temperature (T(c)) at 18 K in K(x)picene has extended the possibility of high-T(c) superconductors in organic materials. Previous experience based on similar hydrocarbons, like alkali-metal doped phenanthrene, suggested that even higher transition temperatures might be achieved in alkali-metals or alkali-earth-metals doped such polycyclic-aromatic-hydrocarbons (PAHs), a large family of molecules composed of fused benzene rings. Here we report the discovery of high-T(c) superconductivity at 33 K in K-doped 1,2:8,9-dibenzopentacene (C(30)H(18)). To our best knowledge, it is higher than any T(c) reported previously for an organic superconductor under ambient pressure. This finding provides an indication that superconductivity at much higher temperature may be possible in such PAHs system and is worthy of further exploration.

[Effects of environmental enrichment on the repair and proliferation of neurons in neonatal rats with hypoxic-ischemic brain damage]

OBJECTIVE

To study the effects of environmental enrichment on neuron proliferation, learning and memory ability and motor ability in neonatal rats with hypoxic-ischemic brain damage (HIBD).

METHODS

One hundred and eight 7-day-old Sprague-Dawley rats were randomly divided into three groups: sham operation (CON group), HIBD and intervention group. HIBD model was prepared according to the classic Rice-Vannucci method. Environmental enrichment was administered for the rats in the intervention group after HIBD inducement. Behavioral tests (Water maze test, Suspension test and Slope test) were performed and the number of neural cells in the left hippocampus was examined 7, 14 and 28 days after intervention.

RESULTS

The pyramid cells in the hippocampus CA1 area in the HIBD group were significantly less than in the CON group at 7, 14 and 28 days (P<0.05). The number of pyramid cells in the hippocampus CA1 area in the intervention group was significantly higher than in the HIBD group (P<0.01) at 7, 14 and 28 days. The hidden platform escape latency period (EL) in the Water maze test was significantly more prolonged and the cross-platform number within 2 minutes was significantly less in the HIBD and the intervention groups than in the CON group at all observed time points (P<0.01). The EL was significantly shorter and the cross-platform number within 2 minutes was significantly higher in the intervention group than in the HIBD group at all observed time points (P<0.01). The maintain time and score in the Suspension test were significantly lower and the time in the Slope test was significantly more prolonged in the HIBD and intervention groups than in the CON group at 7, 14 and 28 days (P<0.01). An increased maintain time and score and a decreased time in the Slope test were found in the intervention group compared with the HIBD group at 14 and 28 days (P<0.01).

CONCLUSIONS

Environmental enrichment can improve motor function, learning and memory ability, and promote the repair and proliferation of neurons in neonatal rats with HIBD.

Antiferromagnetic spin fluctuations above the dome-shaped and full-gap superconducting states of LaFeAsO1-xFx revealed by (75)As-nuclear quadrupole resonance

We report a systematic study by (75)As nuclear-quadrupole resonance in LaFeAsO(1-x)F(x). The antiferromagnetic spin fluctuation found above the magnetic ordering temperature T(N) = 58 K for x = 0.03 persists in the regime 0.04 ≤ x ≤ 0.08, where superconductivity sets in. A dome-shaped x dependence of the superconducting transition temperature T(c) is found, with the highest T(c) = 27 K at x = 0.06, which is realized under significant antiferromagnetic spin fluctuation. With increasing x further, the antiferromagnetic spin fluctuation decreases, and so does T(c). These features resemble closely the cuprates La(2-x)Sr(x)CuO(4). In x = 0.06, the spin-lattice relaxation rate (1/T(1)) below T(c) decreases exponentially down to 0.13T(c), which unambiguously indicates that the energy gaps are fully opened. The temperature variation of 1/T(1) below T(c) is rendered nonexponential for other x by impurity scattering.

Unconventional anisotropic s-wave superconducting gaps of the LiFeAs iron-pnictide superconductor

We have performed high-resolution angle-resolved photoemission spectroscopy on Fe-based superconductor LiFeAs (T(c)=18 K). We reveal multiple nodeless superconducting (SC) gaps with 2Δ/k(B)T(c) ratios varying from 2.8 to 6.4, depending on the Fermi surface (FS). We also succeeded in directly observing a gap anisotropy along the FS with magnitude up to ~30%. The anisotropy is fourfold symmetric with an antiphase between the hole and electron FSs, suggesting complex anisotropic interactions for the SC pairing. The observed momentum dependence of the SC gap offers an excellent opportunity to investigate the underlying pairing mechanism.

[Heart rate variability in children with beta-thalassemia major]

OBJECTIVE

To study the diagnostic value of heart rate variability (HRV) in heart dysfunction in children with beta-thalassemia major (β-TM)by examining the changes of HRV in β-TM children.

METHODS

A 24 hours Holter monitoring electrocardiogram (Holter) was performed in 21 children with β-TM and 15 healthy children (control group). The time domain and frequency domain indexes of HRV in the two groups were compared. The correlation between serum ferritin levels and HRV was evaluated.

RESULTS

The time domain indexes SDNN, rMSSD and PNN50 and the frequency domain indexes very low frequency (VLF), low frequency (LF) and high frequency (HF) in the β-TM group were significantly lower than in the control group (P<0.05). There was no correlation between serum ferritin level and HRV in children with β-TM.

CONCLUSIONS

The autonomic nerve dysfunction exists in children with β-TM. HRV analysis is useful in the prediction of early cardiac dysfunction in children with β-TM.

[Curative effects and safety of deferasirox in treatment of iron overload in children with β-thalassemia major]

OBJECTIVE

To study the effectiveness and safety of deferasirox (DFX) in the treatment of iron overload in children with β-thalassemia major.

METHODS

Twenty-four β-thalassemia major children with iron overload who received regular blood transfusion were randomly enrolled. The serum feritin (SF) levels were measured in the patients after different doses of DFX treatment. The DFX treatment-related adverse events were observed. The values of cardiac MRI T2* and liver MRI T2* were compared between the patients receiving DFX treatment for 5 years and the patients treated with deferoxamine and deferiprone.

RESULTS

The patients with iron overload did not respond to DFX at the initial dose of 20-30 mg/kg•d. However, the SF level decreased significantly after the dose of DFX increased to 30-40 mg/kg•d (U=58, P<0.01). Serum liver transaminase elevation was the most common adverse effect, followed by non-progressive elevation in serum creatinine level. The mean SF level was significantly lower (1748±481 ng/mL vs 3462±1744 ng/mL; P<0.05), in contrast, the liver MRI T2* value was significantly higher (8.5±2.9 ms vs 2.7±1.9 ms; P<0.01) in patients receiving DFX treatment for 5 years than in the controls. There were no significant differences in the cardiac MRI T2* value between the two groups.

CONCLUSIONS

DFX can reduce SF levels in a dose-dependent manner in children with β-thalassemia major. It can significantly lower liver iron overload but not cardiac overload. Serum liver transaminase elevation and non-progressive elevation in serum creatinine level are major adverse effects in DFX treatment.

77Se NMR study of the pairing symmetry and the spin dynamics in K(y)Fe(2-x)Se2

We present a 77Se NMR study of the newly discovered iron selenide superconductor K(y)Fe(2-x)Se2, in which T(c) = 32  K. Below T(c), the Knight shift 77K drops sharply with temperature, providing strong evidence for singlet pairing. Above T(c), Korringa-type relaxation indicates Fermi-liquid behavior. Our experimental results set strict constraints on the nature of possible theories for the mechanism of high-T(c) superconductivity in this iron selenide system.

Electronic structure of optimally doped pnictide Ba0.6K0.4Fe2As2: a comprehensive angle-resolved photoemission spectroscopy investigation

The electronic structure of the Fe-based superconductor Ba(0.6)K(0.4)Fe(2)As(2) is studied by means of angle-resolved photoemission. We identify dispersive bands crossing the Fermi level forming hole-like (electron-like) Fermi surfaces (FSs) around Γ (M) with nearly nested FS pockets connected by the antiferromagnetic wavevector. Compared to band structure calculation findings, the overall bandwidth is reduced by a factor of 2 and the low energy dispersions display even stronger mass renormalization. Using an effective tight banding model, we fitted the band structure and the FSs to obtain band parameters reliable for theoretical modeling and calculation of physical quantities.

Spin waves in the (π,0) magnetically ordered iron chalcogenide Fe1.05Te

We use neutron scattering to show that spin waves in the iron chalcogenide Fe(1.05)Te display novel dispersion clearly different from both the first principles density functional calculations and recent observations in the related iron pnictide CaFe(2)As(2). By fitting to a Heisenberg Hamiltonian, we find that although the nearest-neighbor exchange couplings in the two systems are quite different, their next-nearest-neighbor (NNN) couplings are similar. This suggests that superconductivity in the pnictides and chalcogenides share a common magnetic origin that is intimately associated with the NNN magnetic coupling between the irons.

Retroperitoneal laparoscopic upper-pole nephroureterectomy for duplex kidney anomalies in adult patients

OBJECTIVES

To present our surgical techniques and experience with retroperitoneal laparoscopic upper pole nephroureterectomy for a duplex kidney in adult patients without vesicoureteral reflux.

METHODS

A total of 32 adult patients with a duplex kidney underwent laparoscopic upper pole nephroureterectomy. A 3-port, finger- and balloon-dissecting, retroperitoneal approach was used. The upper pole renal parenchyma was divided circumferentially between the upper and lower poles using a harmonic scalpel, maintaining a margin around the upper pole parenchyma to avoid any possible injury to the lower pole functioning moiety. The urothelium of the remnant upper pole parenchyma was stripped off, and the edges of the remnant upper pole parenchyma were approximated with figure-of-8 stitches. The distal upper pole ureter was mobilized and transected at the point at which the ureter crossed anterior to the iliac vessels. Intravenous urography and renal ultrasonography were performed at 3 and 6 months postoperatively.

RESULTS

All laparoscopic operations were performed successfully without conversion to open surgery. The mean operative time was 83 minutes. The mean blood loss was 18 mL. The mean postoperative hospital stay was 7 days. No intraoperative or major postoperative complications occurred. The intravenous urography and renal ultrasound findings 3 and 6 months postoperatively demonstrated normal pyelography findings and renal function of the preserved lower pole in all patients.

CONCLUSIONS

Retroperitoneal laparoscopic upper pole nephroureterectomy is a safe and effective procedure and an excellent minimally invasive treatment option for the adult patient with a duplex kidney.

Angle-resolved photoemission spectroscopy of the iron-chalcogenide superconductor Fe1.03Te0.7Se0.3: strong coupling behavior and the universality of interband scattering

We have performed angle-resolved photoemission spectroscopy of the iron-chalcogenide superconductor Fe1.03Te0.7Se0.3 to investigate the electronic structure relevant to superconductivity. We observed a holelike Fermi surface (FS) and an electronlike FS at the Brillouin zone center and corner, respectively, which are nearly nested by the Q∼(π,π) wave vector. We do not find evidence for the nesting instability with Q∼(π+δ,0) reminiscent of the antiferromagnetic order in the parent compound Fe1+yTe. We have observed an isotropic superconducting (SC) gap along the holelike FS with the gap size Δ of ∼4 meV (2Δ/kBTc ∼ 7), demonstrating the strong-coupling superconductivity. The observed similarity of low-energy electronic excitations between iron-chalcogenides and iron-arsenides strongly suggests that common interactions which involve Q∼(π,π) scattering are responsible for the SC pairing.

Unusual electronic structure and observation of dispersion kink in CeFeAsO parent compound of FeAs-based superconductors

We report the first comprehensive high-resolution angle-resolved photoemission measurements on CeFeAsO, a parent compound of FeAs-based high temperature superconductors with a magnetic-structural transition at ∼150 K. In the magnetic-ordering state, four holelike Fermi surface sheets are observed near Γ(0,0), and the Fermi surface near M(±π,±π) shows a tiny electronlike pocket at M surrounded by four strong spots. The unusual Fermi surface topology deviates strongly from the band structure calculations. The electronic signature of the magnetic-structural transition shows up in the dramatic change of the quasiparticle scattering rate. A dispersion kink at ∼25 meV is observed for the first time in the parent compound of Fe-based superconductors.

Band-dependent quasiparticle dynamics in single crystals of the Ba(0.6)K(0.4)Fe2As2 superconductor revealed by pump-probe spectroscopy

We report on band-dependent quasiparticle dynamics in Ba(0.6)K(0.4)Fe2As2 (Tc=37 K) measured using ultrafast pump-probe spectroscopy. In the superconducting state, we observe two distinct relaxation processes: a fast component whose decay rate increases linearly with excitation density and a slow component with an excitation density independent decay rate. We argue that these two components reflect the recombination of quasiparticles in the two hole bands through intraband and interband processes. We also find that the thermal recombination rate of quasiparticles increases quadratically with temperature. The temperature and excitation density dependence of the decays indicates fully gapped hole bands and nodal or very anisotropic electron bands.

Observation of Dirac cone electronic dispersion in BaFe2As2

We performed an angle-resolved photoemission spectroscopy study of BaFe2As2, which is the parent compound of the so-called 122 phase of the iron-pnictide high-temperature superconductors. We reveal the existence of a Dirac cone in the electronic structure of this material below the spin-density-wave temperature, which is responsible for small spots of high photoemission intensity at the Fermi level. Our analysis suggests that the cone is slightly anisotropic and its apex is located very near the Fermi level, leading to tiny Fermi surface pockets. The bands forming the cone show an anisotropic leading edge gap away from the cone that suggests a nodal spin-density-wave description.

Ultrafast pump-probe study of phase separation and competing orders in the underdoped (Ba,K)Fe2As2 superconductor

We report measurements of quasiparticle relaxation dynamics in the high-temperature superconductor (Ba,K)Fe2As2 in optimally doped, underdoped, and undoped regimes. In the underdoped sample, spin-density wave (SDW) order forms at approximately 85 K, followed by superconductivity at approximately 28 K. We find the emergence of a normal-state order that suppresses SDW at a temperature T{*} approximately 60 K and argue that this normal-state order is a precursor to superconductivity.

Lattice distortion and magnetic quantum phase transition in CeFeAs(1-x)P(x)O

We use neutron diffraction to study the structural and magnetic phase diagram of CeFeAs(1-x)P(x)O. We find that replacing the larger arsenic with smaller phosphorus in CeFeAs(1-x)P(x)O simultaneously suppresses the AFM order and orthorhombic distortion near x=0.4, thus suggesting the presence of a magnetic quantum critical point. Our detailed structural analysis reveals that the pnictogen height is an important controlling parameter for their electronic and magnetic properties, and may play an important role in electron pairing and superconductivity of these materials.

Band structure and fermi surface of an extremely overdoped iron-based superconductor KFe2As2

We have performed high-resolution angle-resolved photoemission spectroscopy on heavily overdoped KFe_{2}As_{2} (transition temperature T_{c} = 3 K). We observed several renormalized bands near the Fermi level with a renormalization factor of 2-4. While the Fermi surface around the Brillouin-zone center is qualitatively similar to that of optimally doped Ba_{1-x}K_{x}Fe_{2}As_{2} (x = 0.4; T_{c} = 37 K), the Fermi surface topology around the zone corner (M point) is markedly different: the two electron Fermi surface pockets are completely absent due to an excess of hole doping. This result indicates that the electronic states around the M point play an important role in the high-T_{c} superconductivity of Ba_{1-x}K_{x}Fe_{2}As_{2} and suggests that the interband scattering via the antiferromagnetic wave vector essentially controls the T_{c} value in the overdoped region.

Fermi surface topology and low-lying quasiparticle dynamics of parent Fe1+xTe/Se superconductor

We report the first photoemission study of Fe1+xTe-the host compound of the newly discovered iron-chalcogenide superconductors (maximum Tc approximately 27 K). Our results reveal a pair of nearly electron-hole compensated Fermi pockets, strong Fermi velocity renormalization, and an absence of a spin-density-wave gap. A shadow hole pocket is observed at the "X" point of the Brillouin zone which is consistent with a long-range ordered magnetostructural ground state. No signature of Fermi surface nesting instability associated with Q=(pi/2,pi/2) is observed. Our results collectively reveal that the Fe1+xTe series is different from the undoped phases of the high Tc pnictides and likely harbor an unusual mechanism for superconductivity and magnetic order.

Multiple phase transitions in single-crystalline Na_{1-delta}FeAs

Specific heat, resistivity, susceptibility, and Hall coefficient measurements were performed on high-quality single-crystalline Na_{1-delta}FeAs. This compound is found to undergo three successive phase transitions at around 52, 41, and 23 K, which correspond to structural, magnetic, and superconducting transitions, respectively. The Hall effect result indicates the development of energy gap at low temperature due to the occurrence of spin-density-wave instability. Our results provide direct experimental evidence of the magnetic ordering in the nearly stoichiometric NaFeAs.