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Weeds are one of the main problems faced by agronomists, which are the cause of large losses of crops in many farmlands. Screening of novel biocontrol agents against weeds is highly desired to control a wide variety of weeds. The endophytic fungal isolate HL-1 was isolated from the phyllosphere of Cirsium setosum indigenous to agricultural fields of Hualong, Qinghai Province. The isolate was evaluated for its herbicidal activity against target weeds and its safety to major crops. The feasibility of solid substrate fermentation for the spore production of isolate HL-1 has been examined. The results indicated that the disease incidences of Galium aparine, Chenopodium album, Malva crispa, and Polygonum lapathifolium applied with HL-1 filtrate were 96.24%, 87.48%, 55.71%, and 65.48%, and the fresh weight reductions were 69.04%, 72.02%, 66.12%, and 58.03%, respectively. The filtrate was safe to Triticum aestivum and Vicia faba and slightly pathogenic to Brassica napus, Pisum sativum, and Hordeum vulgare. The strain was validated as Alternaria alternata by cultural characteristic and internal transcribed spacer sequencing. Optimization of the carbon and nitrogen sources for cultural media and materials for solid-state fermentation demonstrated that strain HL-1 had better colony growth and spore yield with the optimal carbon source of glucose, nitrogen source of yeast extract, and the optimal material was rapeseed cake. The optimal fermentation conditions of HL-1 are a temperature of 25 ℃, an inocula age of 72 h, initial moisture content of 40%, and an inoculated quantity of 8%. Its formulation showed a strong herbicidal activity on the tested weeds in both pot and field experiments, especially Stellaria media. Thus, phyllosphere microbiota is considered to be an important resource for implementing new biological herbicides for weed control, and this work provides a formulation of a mycoherbicide made up of spores produced by HL-1. [ABSTRACT FROM AUTHOR]

Adenosine triphosphate–binding cassette subfamily B member 1 (ABCB1), also known as permeability glycoprotein, multidrug-resistant protein 1, or cluster of differentiation 243 (CD243), is a crucial protein for purging foreign substances from cells. The functions of ABCB1 have been investigated extensively for their roles in cancer, stem cells, and drug resistance. Abundant pharmacogenetic studies have been conducted on ABCB1 and its association with treatment responsiveness to various agents, particularly chemotherapeutic and immunomodulatory agents. However, its functions in the skin and implications on dermatotherapeutics are far less reported. In this article, we reviewed the roles of ABCB1 in dermatology. ABCB1 is expressed in the skin and its appendages during drug delivery and transport. It is associated with treatment responsiveness to various agents, including topical steroids, methotrexate, cyclosporine, azathioprine, antihistamines, antifungal agents, colchicine, tacrolimus, ivermectin, tetracycline, retinoid acids, and biologic agents. Moreover, genetic variation in ABCB1 is associated with the pathogenesis of several dermatoses, including psoriasis, atopic dermatitis, melanoma, bullous pemphigoid, Behçet disease, and lichen planus. Further investigation is warranted to elucidate the roles of ABCB1 in dermatology and the possibility of enhancing therapeutic efficacy through ABCB1 manipulation. [ABSTRACT FROM AUTHOR]

Background: First Irish National Corneal Transplant Registry report. Aim: To report about current corneal transplantation practices in Ireland including patient demographics, indications and types of transplant performed and to compare the findings with other developed countries. Methods: Nationwide retrospective review of the corneal transplants performed in Ireland between 2016 and 2019. Results: Overall, 536 keratoplasties were carried out: 256 (47.8%) Penetrating Keratoplasties (PK), 212 (39.6%) Descemet Stripping Automated Endothelial Keratoplasties (DSAEK), 30 (5.6%) Descemet Membrane Endothelial Keratoplasties (DMEK), and 25 (4.7%) Deep Anterior Lamellar Keratoplasties (DALK). The most common indication was Keratoconus (KC, 19%), followed by Fuchs endothelial dystrophy (FED, 18.8%), and Pseudophakic bullous keratopathy (PBK, 17%). KC (34%) and re-grafting (17%) were the leading indications for PK, whereas FED and PBK were the major indications for DSAEK (38% and 33%) and DMEK (67% and 20%), respectively. During the period studied, the number of transplants increased from 11.3 to 14 grafts per month. The number of PKs remained stable, whereas Endothelial Keratoplasties, DSAEK and DMEK, increased (3.8 to 5.6 and 0.2 to 1.6 per month, respectively), becoming the most commonly performed grafts since 2018. Only a small number of DALK were performed. Conclusions: Corneal transplantation in Ireland is following international trends as endothelial procedures have become the most common approach since 2018. However, a low overall number of transplants is performed in Ireland compared with other countries suggesting that care pathways should be implemented to improve access to corneal transplantation. [ABSTRACT FROM AUTHOR]

Weyl semimetals host chiral fermions with distinct chiralities and spin textures. Optical excitations involving those chiral fermions can induce exotic carrier responses, and in turn lead to novel optical phenomena. Here, we discover strong coherent terahertz emission from Weyl semimetal TaAs, which is demonstrated as a unique broadband source of the chiral terahertz wave. The polarization control of the THz emission is achieved by tuning photoexcitation of ultrafast photocurrents via the photogalvanic effect. In the near-infrared regime, the photon-energy dependent nonthermal current due to the predominant circular photogalvanic effect can be attributed to the radical change of the band velocities when the chiral Weyl fermions are excited during selective optical transitions between the tilted anisotropic Weyl cones and the massive bulk bands. Our findings provide a design concept for creating chiral photon sources using quantum materials and open up new opportunities for developing ultrafast opto-electronics using Weyl physics. Here, the authors report photon-energy-dependent terahertz emission and ultrafast photocurrents from the Weyl semimetal, TaAs. The polarization control of the emission is achieved by excitation of the photocurrents whose direction and magnitude depend on the polarization of the femtosecond optical pulses. [ABSTRACT FROM AUTHOR]

Bisphosphonates (BPs) are first-line drugs for the treatment of osteoporotic fractures, but long-term use of BP reduces bone turnover and is associated with atypical femur fractures (AFFs). Additionally, BP treatment may cause delayed fracture healing or nonunion, which makes AFF treatment difficult. The incidence of AFF is generally low. In fact, there are only a few clinical reports of AFF and there is no controlled study on AFF treatment. Herein, we report a case of multiple osteoporotic fractures. After 5 years of BP treatment, left and right AFFs occurred within 2 years. The fracture types and surgical operations were the same, but the level of bone metabolism and drug treatment were different. The right AFF healed well following teriparatide initiation compared with non-healed left AFF with BP continuation; thus, our case can be considered a self-controlled study. Furthermore, we have reviewed the diagnosis and treatment of this case in detail and analyzed and investigated the potential causes of the different outcomes of AFFs between the two sides to inform the clinical treatment of atypical fractures. Mini Abstract We report a case of bilateral AFFs. The surgical treatments were the same, but the final treatment outcomes were different with or without teriparatide treatment. We investigated the potential causes of the different outcomes of AFFs between the two sides to inform the clinical treatment of AFFs. [ABSTRACT FROM AUTHOR]

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

Hot roll bonding of 4343/4A60 aluminum alloy has been performed in the Gleeble-3500 thermal simulator. The bonding process constitutive behavior has been analyzed. The results show that the peak flow stress decreases with the deformation temperature and strain rate reduction. An Arrhenius-type constitutive equation is used to describe the constitutive behavior of the hot-rolled 4343/4A60 aluminum alloy with the thermal deformation activation energy Q = 118.48 kJ/mol. The alloy microstructure and dynamic recrystallization are studied using the optical microscope. It is revealed that in the temperature range between 573 and 623 K the dynamic recovery has a strong effect on the alloy microstructure evolution. It has been also concluded that the dynamic recovery is the basic softening mechanism of 4343/4A60 composite. [ABSTRACT FROM AUTHOR]

In 1929, H. Weyl proposed that the massless solution of the Dirac equation represents a pair of a new type of particles, the so-called Weyl fermions. However, their existence in particle physics remains elusive after more than eight decades. Recently, significant advances in both topological insulators and topological semimetals have provided an alternative way to realize Weyl fermions in condensed matter, as an emergent phenomenon: when two non-degenerate bands in the three-dimensional momentum space cross in the vicinity of the Fermi energy (called Weyl nodes), the low-energy excitations behave exactly as Weyl fermions. Here we report the direct observation in TaAs of the long-sought-after Weyl nodes by performing bulk-sensitive soft X-ray angle-resolved photoemission spectroscopy measurements. The projected locations at the nodes on the (001) surface match well to the Fermi arcs, providing undisputable experimental evidence for the existence of Weyl fermionic quasiparticles in TaAs. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) topological Dirac semimetals (TDSs) are a recently proposed state of quantum matter that have attracted increasing attention in physics and materials science. A 3D TDS is not only a bulk analogue of graphene; it also exhibits non-trivial topology in its electronic structure that shares similarities with topological insulators. Moreover, a TDS can potentially be driven into other exotic phases (such as Weyl semimetals, axion insulators and topological superconductors), making it a unique parent compound for the study of these states and the phase transitions between them. Here, by performing angle-resolved photoemission spectroscopy, we directly observe a pair of 3D Dirac fermions in Cd3As2, proving that it is a model 3D TDS. Compared with other 3D TDSs, for example, β-cristobalite BiO2 (ref. ) and Na3Bi (refs , ), Cd3As2 is stable and has much higher Fermi velocities. Furthermore, by in situ doping we have been able to tune its Fermi energy, making it a flexible platform for exploring exotic physical phenomena. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to evaluate the diagnostic imaging findings and treatment results of patients with idiopathic intracranial hypotension (IIH) due to cerebrospinal fluid (CSF) leaks. Methods: Between February 2009 and April 2012, 26 IIH patients (15 men, median age 49 years) presenting with orthostatic headache ( n = 20) and/or with spontaneous subdural effusions or subarachnoid hemorrhage ( n = 19) were enrolled. Twenty-three patients underwent a whole spine CT and MRI myelography, starting 45 min after the intrathecal injection of 9 cc of iomeprol (Imeron 300 M) and 1 cc of gadobutrolum (Gadovist). Three patients only underwent MR myelography after intrathecal gadobutrolum injection. Adjacent to the level(s) of the detected CSF leak(s) along the nerve roots, 20 cc of fresh venous blood with 0.5 cc Gadovist was injected epidurally (blood patch, BP). The distribution of the BP was visualized by MRI the following day. Treatment results were evaluated clinically and by myelography 2 weeks after the application of the BP. Retreatment was offered to patients with persistent symptoms and continued CSF leakage. Results: CSF leaks were detected at the cervical ( n = 12), thoracic ( n = 25), or lumbar ( n = 21) spine. In 23 patients, more than one spinal segment was affected. One patient refused treatment. BP were applied in one ( n = 9) or several ( n = 16) levels. Clinical and/or radiological improvement was achieved after one ( n = 16), two ( n = 5), three ( n = 3), or five ( n = 1) BPs. Conclusion: CT and MRI myelography allow the reliable detection of spinal CSF leaks. The targeted and eventually repeated epidural BP procedure is a safe and efficacious treatment. [ABSTRACT FROM AUTHOR]

Expression of survivin has been reported to be correlated with shorter survival in patients with non-small cell lung cancer (NSCLC), and overexpression of survivin may lead to radioresistance in various human cancers. In this study, we inhibited survivin expression by using an adenoviral vector (AdsiSurvivin)-mediated RNA interference to elucidate the combined effect of survivin-targeting gene therapy and radiotherapy on the NSCLC cells. Our data showed that AdsiSurvivin exerted survivin gene silencing, induced apoptosis, and significantly attenuated the growth potential in NSCLC cells within 72 h after infection. The combined treatment modalities with AdsiSurvivin infection and radiation were significantly more potent on cell-growth inhibition than monotherapy. In H1650, H460, A549, and H1975 human NSCLC cells, the survival ratios of AdsiSurvivin-treated groups at multiplicity of infection of 25 and 50 were significantly lower than those of control groups at varying radiation dose (0–8 Gy; three-way analysis of variance, P<0.05). The cytotoxicity of combined AdsiSurvivin infection and irradiation increased in a dose-dependent manner in both the virus and the irradiation treatment. Knockdown of the survivin gene expression seems to be a promising treatment strategy for NSCLC. Our data warrant the need for further effort to develop survivin-targeted radiosensitizer for lung cancer treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND AND AIMS: This study retrospectively examined the characteristics of metabolic syndrome in an aged population and assessed the risk factors for these subjects. METHODS: A total of 1332 aged subjects (>/=65 years; mean age 71.0+/-5.0 years) were enrolled from 6903 subjects recruited from the Department of Health Management at Chang Gung Medical Center. Of these 6903 subjects, 1665 (814 females and 851 males) were diagnosed with metabolic syndrome. Whole body three-dimensional (3- D) laser scanning was employed for anthropometric measurements. Furthermore, health index (HI) was derived by the following equation: HI = (body weight x 2 x waist area) / [body height2 x (breast area + hip area)]. RESULTS: Among the 6903 subjects, no significant difference in gender was noted between groups with and without metabolic syndrome (p=0.142). For subjects >64 years, the incidence of metabolic syndrome in females is higher than in males. Subjects are categorized into four groups based on age and whether they had metabolic syndrome. Group A (4402 cases) consists of subjects <65 years old without metabolic syndrome. Group B (836 cases) comprises subjects >64 years old and without metabolic syndrome. Group C (1169 cases) contains subjects <65 years old with metabolic syndrome and group D (496 cases) is composed of subjects >64 years old with metabolic syndrome. Of the aged 1332 subjects, 595 were females (mean age, 70.6+/-4.6 years) and 737 were males (mean age, 71.3+/-5.3years), 37.2% (496/1332) had metabolic syndrome, 19.9% had DM and 21.8% had hypertension. These subjects had decreased BMI with age. Additionally, WHR peaked at an age range of 75-79 years. Of the aged subjects, also overweight, 42.8% and 33.6% were diagnosed with hypertension and DM, respectively; both ratios higher than those for non-overweight subjects (25.3% and 26.2%, respectively). Of the four groups in this study, the ratios for DM, hypertension, and WHR, HI, and LDL levels progressively increased through groups A to D. WBC count differs statistically significantly between these groups. Statistical analysis of WBC count, RBC and hemoglobin (Hb) with different parameters demonstrates significant elevation of WBC counts with the components of metabolic syndrome in aged subjects. CONCLUSIONS: WBC count, RBC count and Hb are associated with metabolic syndrome components in younger and old adults of both genders. The incidence of metabolic syndrome marker increased after menopause onset in the female population in this study. [ABSTRACT FROM AUTHOR]

In this study ibuprofen (50.0 mg/kg, i.p.), rofecoxib (10.0 mg/kg, i.p.) and thalidomide (50.0 mg/kg, oral) were shown to prevent vincristine-induced mechanical hyperalgesia. Sprague-Dawley rats were injected every other day with vincristine (0.1 mg/kg) over 13 days. The animals were cotreated daily with vehicle (saline), ibuprofen, rofecoxib or thalidomide throughout the period of vincristine treatment. Mechanical withdrawal threshold to punctuate and radiant heat stimuli were determined prior to and then on alternate days throughout the treatment period. Vincristine vehicle-treated animals developed marked mechanical hyperalgesia from day 5 of chemotherapy and this lasted until the end of the experiment. Thermal thresholds were not altered by the administration of vincristine vehicle. Animals in the vincristine vehicle group neither gained nor lost weight during the treatment period. All three active drugs showed an antihyperalgesic effect on the responses to mechanical stimulation of the hind paw that was significant from day 5 for ibuprofen and thalidomide and from day 7 for rofecoxib. Thermal thresholds increased after the administration of both the NSAIDs and thalidomide. Rofecoxib was the only drug to show any beneficial effect in protecting the animals from failure to gain body weight. [ABSTRACT FROM AUTHOR]

First-principles calculations with the full-potential linearized augmented plane-wave (FP-LAPW) method have been performed to investigate detailed electronic and linear optical properties of Sr2CuO2Cl2, which is a classical low-dimensional antiferromagnet (AFM) charge transfer (CT) insulator. Within the local-spin-density approximation (LSDA) plus the on-site Coulomb interaction U (LADA+U) added on Cu 3d orbitals, our calculated band gap and spin moments are well consistent with the experimental and other theoretical values. The energy dispersion relation agrees well with the angle resolved photoemission measurements. Its linear optical properties are calculated within the electric-dipole approximation. The absorption spectrum is found to agree well with the experimental result. [ABSTRACT FROM AUTHOR]

: The structural, electronic, and optical properties of 4 Å single-walled carbon nanotubes (SWNTs) contained inside the zeolite channels have been studied based upon the density-functional theory in the local-density approximation (LDA). Our calculated results indicate that the relaxed geometrical structures for the smallest SWNTs in the zeolite channels are much different from those of the ideal isolated SWNTs, producing a great effect on their physical properties. It is found that all three kinds of 4 Å SWNTs can possibly exist inside the Zeolite channels. Especially, as an example, we have also studied the coupling effect between the ALPO4-5 zeolite and the tube (5,0) inside it, and found that the zeolite has real effects on the electronic structure and optical properties of the inside (5,0) tube. [ABSTRACT FROM AUTHOR]

Coronary artery bypass graft (CABG) operations consume more health care resources than any other single procedure. The objective of this study was to develop a computer simulation model that can be used to predict costs and patient outcomes of CABG surgery. The analysis is based on a systems dynamic model developed using STELLA software. Two sets of data from Medicare patients who underwent CABG operations at Methodist Hospital of Indiana were used to construct and validate the model. The model predictions of length of hospital stay, use of specialists in caring for patients, costs and postoperative functional status are reasonably close to actual data on patients who underwent CABG surgery. The analysis indicates the most important factors affecting costs and outcomes are gender, age, whether or not the surgery is a reoperation and whether the patient experiences postoperative complications. The model can be used to predict costs and outcomes for a patient population from a small set of preoperative characteristics (i.e., age, gender, DRG, whether the surgery is a reoperation, and the patient's operative status). A second potential use of the model is to answer clinical questions such as do the costs and risks of CABG operations outweigh the benefits for patients with certain risk factors. [ABSTRACT FROM AUTHOR]

Purpose: The authors report their experience with the treatment of intrahepatic bile duct strictures associated with hepatolithiasis.Methods: Eighty patients had multiple postoperative retained intrahepatic duct stones trapped behind intrahepatic biliary strictures. Before stone extraction, the strictures were opened gradually by semirigid dilators, followed by stent placement to create enough patency for stone removal. All procedures were carried out through the T-tube tracts and were aided by cholangioscopy and electrohydraulic lithotripsy.Results: Complete clearance of stones was achieved in 69 patients. Failure to dilate the strictures was due to acute and multiple ductal angulations. These included the right posterior inferior intrahepatic duct at its junction with the left intrahepatic ducts when it was more than 2 cm distal to the hepatic bifurcation, when the angle between the T-tube tract and the common bile duct was smaller than 90 degrees, and when stones were located in peripheral intrahepatic ducts with more than five angulations.Conclusion: This technique is considered safe and effective for complicated hepatolithiasis with intrahepatic biliary strictures. [ABSTRACT FROM AUTHOR]

The withdrawal reflex pathways to hindlimb muscles have an elaborate spatial organization in the rat. In short, the distribution of sensitivity within the cutaneous receptive field of a single muscle has a spatial pattern that is a mirror image of the spatial pattern of the withdrawal of the skin surface ensuing on contraction in the respective muscle. In the present study, a search for neurones encoding the specific spatial input-output relationship of withdrawal reflexes to single muscles was made in the lumbosacral spinal cord in halothane/nitrous oxide-anaesthetized rats. The cutaneous receptive fields of 147 dorsal horn neurones in the L4-5 segments receiving a nociceptive input and a convergent input from A and C fibres from the hindpaw were studied. The spatial pattern of the response amplitude within the receptive fields of 118 neurones was quantitatively compared with those of withdrawal reflexes to single muscles. Response patterns exhibiting a high similarity to those of withdrawal reflexes to single muscles were found in 27 neurones located in the deep dorsal horn. Twenty-six of these belonged to class 2 (responding to tactile and nociceptive input) and one belonged to class 3 (responding only to nociceptive input). None of the neurones tested ( n=20) with reflex-like response patterns could be antidromically driven from the upper cervical cord, suggesting that they were spinal interneurones. With some overlap, putative interneurones of the withdrawal reflexes to the plantar flexors of the digits, the plantar flexors of the ankle, the pronators, the dorsiflexors of the ankle, and a flexor of the knee, were found in succession in a mediolateral direction. It is concluded that neurones that are able to encode the specific spatial input-output organization of the withdrawal reflexes to single muscles do exist in the deep dorsal horn. Such reflex encoders appear to have a 'musculotopic' organization. A hypothesis of the organization of the withdrawal reflex system is presented. [ABSTRACT FROM AUTHOR]

Few clinicians in the United States use computers during patient encounters and many still worry that computers will depersonalize their interactions with patients. This case study describes patient and clinician reactions to a computer-based health appraisal system. Findings showed no difference in any aspect of patient satisfaction between computer and non-computer groups. Use of a computer in the consulting room neither depersonalized nor enhanced patient satisfaction. Clinicians (in this case, nurse practitioners and physician assistants) were willing to use the system, which they perceived as having benefits for patient care, but were concerned about the increased time required for exams, effort required to learn the system while still interacting appropriately with the patient, increased monitoring of their performance, and other organizational issues. Clinicians who used the system showed a higher tolerance for uncertainty and communicated more frequently with each other and with others throughout the department. Implementation was slowed by the need to demonstrate the monetary value of the system. [ABSTRACT FROM AUTHOR]

Abstract. The distribution and annealing behavior of defects in crystalline silicon caused by 7 x 10[sup 16]/cm[sup 2] He[sup +] implantation were investigated by slow-positron annihilation technique, transmission electron microscopy, Rutherford backscattering, and channeling spectroscopy. It was found that small vacancy clusters were induced in the surface region and big clusters (microbubbles) formed around the projected range in which the crystal was heavily damaged by the implantation. The small vacancy clusters in the near-surface region start to disappear at 300 Celsius and can be removed at temperatures up to 700 Celsius by dissociation and diffusing to the damaged region. This results in the growth of voids. The severely damaged region around the projected range begins to anneal out at temperatures higher than 600 Celsius, and He is released, leaving voids embedded inside the crystalline silicon. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The multi-scale time-space regimes of the low-frequency convective activity over the maritime continent and tropical western Pacific are investigated using the monthly infrared radiance black body temperature (IRTBB) over a latitude band of 5S--9S, 80E--16OW for the time period of 1980--1993. The complex Morlet wavelet transform and the complex empirical orthogonal function (CEOF) analysis are used. The zonal mean of the monthly IRTBB is dominated by the annual cycle which is influenced by a monsoon regime. An interannual signal around the time scale of 4.8-year and a decadal signal are obvious. In the zonal deviation, each CEOF represents a particular spatial regime; its corresponding principal component exhibits different multi-scale temporal behavior. The first leading component represents the variability due to large scale land-ocean distribution (the maritime continent, the Indian Ocean and the western Pacific) related to monsoon, with a dominantannual time scale. The second leading component represents the fluctuation of Walker circulation, associated with the El Nino-Southern Oscillation (ENSO) events having a main time scale around 4.8-year and the quasi-biennial oscillation (QBO) around 2.4-year. The third leading component represents the variability due to small-scale land--ocean distribution (Java, New Guinea and the surrounding seas), with a dominant annual time scale. The main time scales in all the components seem to be modulated by longer time scales in either amplitude or frequency or both. Different time scales, as well as their in-phase interference, may play different roles in developing an individual ENSO event. The 1982/1983 event is dominated by an enhanced QBO. The 1986/1987 event is dominated by an enhanced 4.8-year oscillation. The 1991 and 1993 events may have resulted from an in-phase interference amongseveral interannual time scales, abnormal annual cycles, and also high-frequency variability. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) topological Dirac semimetals (TDSs) are a recently proposed state of quantum matter that have attracted increasing attention in physics and materials science. A 3D TDS is not only a bulk analogue of graphene; it also exhibits non-trivial topology in its electronic structure that shares similarities with topological insulators. Moreover, a TDS can potentially be driven into other exotic phases (such as Weyl semimetals, axion insulators and topological superconductors), making it a unique parent compound for the study of these states and the phase transitions between them. Here, by performing angle-resolved photoemission spectroscopy, we directly observe a pair of 3D Dirac fermions in Cd3As2, proving that it is a model 3D TDS. Compared with other 3D TDSs, for example, β-cristobalite BiO2 (ref. ) and Na3Bi (refs , ), Cd3As2 is stable and has much higher Fermi velocities. Furthermore, by in situ doping we have been able to tune its Fermi energy, making it a flexible platform for exploring exotic physical phenomena. [ABSTRACT FROM AUTHOR]