Observation of a singular Weyl point surrounded by charged nodal walls in PtGa.

Constrained by the Nielsen-Ninomiya no-go theorem, in all so-far experimentally determined Weyl semimetals (WSMs) the Weyl points (WPs) always appear in pairs in the momentum space with no exception. As a consequence, Fermi arcs occur on surfaces which connect the projections of the WPs with opposite chiral charges. However, this situation can be circumvented in the case of unpaired WP, without relevant surface Fermi arc connecting its surface projection, appearing singularly, while its Berry curvature field is absorbed by nontrivial charged nodal walls. Here, combining angle-resolved photoemission spectroscopy with density functional theory calculations, we show experimentally that a singular Weyl point emerges in PtGa at the center of the Brillouin zone (BZ), which is surrounded by closed Weyl nodal walls located at the BZ boundaries and there is no Fermi arc connecting its surface projection. Our results reveal that nontrivial band crossings of different dimensionalities can emerge concomitantly in condensed matter, while their coexistence ensures the net topological charge of different dimensional topological objects to be zero. Our observation extends the applicable range of the original Nielsen-Ninomiya no-go theorem which was derived from zero dimensional paired WPs with opposite chirality.

Breast ductal carcinoma in situ with micro-invasion versus ductal carcinoma in situ: a comparative analysis of clinicopathological and mammographic findings.

AIM: To determine the differences in clinicopathological and mammographic findings between ductal carcinoma in situ (DCIS) and ductal carcinoma in situ with micro-invasion (DCIS-MI) and explore clinicopathological and mammographic factors associated with DCIS-MI. MATERIALS AND METHODS: All DCIS patients with or without micro-invasion who underwent preoperative mammography at The Affiliated Hospital of Qingdao University from January 2016 through June 2020 were identified retrospectively. The correlations of clinicopathological findings with DCIS-MI were evaluated using univariate and multivariate binary logistic regression analyses. Imaging findings were compared between the groups by using the Pearson chi-square test. RESULTS: A total of 445 DCIS lesions and 151 DCIS-MI lesions were included in the final analysis. Large extent (≥2.7 cm), high nuclear grade, comedo-type, negative progesterone receptor (PR), negative oestrogen receptor (ER), high Ki-67 and axillary lymph node metastasis were more frequently found in DCIS-MI than in DCIS (all p<0.05), and the first four of these were found to be independent predictors of DCIS-MI in the multivariate analysis (all p<0.05). Regarding imaging findings, compared to DCIS, DCIS-MI showed fewer occult lesions and more lesions with calcifications in mass, asymmetry, and architectural distortion (p=0.004). Grouped calcifications were usually associated with DCIS, while regional calcifications were commonly found in DCIS-MI (p<0.05). CONCLUSION: Large extent, high nuclear grade, comedo-type and negative PR were found to be independent predictors of DCIS-MI. Lesions with calcifications and regional calcifications were more likely associated with DCIS-MI on mammography.

[Prospective randomized controlled study on clinical effects of autologous skin paste in repairing medium-thickness skin donor site wounds].

Objective: To explore the clinical effects of autologous skin paste in repairing medium-thickness skin donor site wounds. Methods: The prospective randomized controlled research method was applied. From October 2018 to December 2019, 18 patients with flame burn or hydrothermal scald, conforming to the inclusion criteria were admitted to Jinhua Hospital Affiliated to Zhejiang University School of Medicine, including 15 males and 3 females, aged (45±6) years. The wounds were repaired with medium-thickness skin grafts from thigh, and the wound area was (121±33) cm2 after medium-thickness skin grafting. The medium-thickness skin donor site wound in each patient was divided into 2 wounds in equal area and allocated into autologous skin paste group and conventional treatment group by flipping a coin, with 18 wounds in each group. The wounds in autologous skin paste group were repaired with skin paste prepared with remaining skin fragments after autologous medium-thickness skin grafting, and the wounds in conventional treatment group were covered with petroleum jelly gauze and fixed with sterile gauze. On 3, 7, 14, and 21 d after operation, the wound healing in 2 groups was observed, and the wound healing rate was calculated. The wound healing time in 2 groups was recorded. Occurrences of wound subcutaneous effusion and infection on 3, 7, 14, and 21 d after operation and wound ulceration in 3 months after operation were observed. In 6 months after operation, the Vancouver Scar Scale (VSS) was used to evaluate the scar formation of wounds in 2 groups. Data were statistically analyzed with analysis of variance for repeated measurement, chi-square test, and group t test. Results: The wounds in 2 groups did not heal on 3 and 7 d after operation. The wound healing rate in autologous skin paste group was (29.8±2.5)% and (95.6±4.7)% on 14 and 21 d after operation, which were significantly higher than (25.8±2.9)% and (82.6±8.9)% in conventional treatment group (t=4.3, 5.6, P<0.01). The wound healing time in autologous skin paste group was (21.8±1.6) d, which was significantly shorter than (25.6±2.0) d in conventional treatment group (t=6.24, P<0.01). On 3, 7, 14, and 21 d after operation, there were no complications such as subcutaneous effusion or infection in wounds of 2 groups. In 3 months after operation, ulceration occurred in wounds of 2 patients in autologous skin paste group, which was significantly less than 12 patients in conventional treatment group (χ2=11.688, P<0.01). The ulcerated wounds healed after dressing changes. In 6 months after operation, the VSS score of wounds in autologous skin paste group was (9.1±1.1) points, which was significantly lower than (11.3±1.2) points in conventional treatment group (t=-5.75, P<0.01). Conclusions: The remaining skin fragments after autologous medium-thickness skin grafting prepared into skin paste to repair medium-thickness skin donor site wounds can shorten wound healing time, improve wound healing quality, and reduce degree of scar hyperplasia, with a good clinical effect.

Unconventional Transverse Transport above and below the Magnetic Transition Temperature in Weyl Semimetal EuCd_{2}As_{2}.

As exemplified by the growing interest in the quantum anomalous Hall effect, the research on topology as an organizing principle of quantum matter is greatly enriched from the interplay with magnetism. In this vein, we present a combined electrical and thermoelectrical transport study on the magnetic Weyl semimetal EuCd_{2}As_{2}. Unconventional contribution to the anomalous Hall and anomalous Nernst effects were observed both above and below the magnetic transition temperature of EuCd_{2}As_{2}, indicating the existence of significant Berry curvature. EuCd_{2}As_{2} represents a rare case in which this unconventional transverse transport emerges both above and below the magnetic transition temperature in the same material. The transport properties evolve with temperature and field in the antiferromagnetic phase in a different manner than in the paramagnetic phase, suggesting different mechanisms to their origin. Our results indicate EuCd_{2}As_{2} is a fertile playground for investigating the interplay between magnetism and topology, and potentially a plethora of topologically nontrivial phases rooted in this interplay.

[Effect of autologous skin paste on repairing wound of donor site of medium-thickness skin graft].

Objective: To explore the effect of autologous skin paste on repairing wound of medium-thickness skin donor site. Methods: The prospective randomized controlled research method was applied. From October 2018 to December 2019, 18 patients with flame burn or hydrothermal scald, met the inclusion criteria were admitted to Jinhua Hospital Affiliated to Zhejiang University School of Medicine, including 15 males and 3 females, aged (45±6) years, and the wounds were repaired with medium-thickness skin grafts. The wound area after medium-thickness skin grafting was (121±33) cm2. The wound of donor site of medium-thickness skin graft in each patient was divided into 2 wounds in equal area and included into autologous skin paste group and conventional treatment group with random number table, with 18 wounds in each group.The wounds in autologous skin paste group were repaired with skin paste prepared with remaining skin fragments after autologous medium-thickness skin grafting, and the wounds in conventional treatment group were repaired with petroleum jelly gauze and sterile gauze. On 3, 7, 14, 21 d after operation, the wound healing in 2 groups was observed, and the wound healing rate was calculated. The wound healing time in 2 groups was recorded. Occurrences of subcutaneous effusion and infection on 3, 7, 14, 21 d after operation and wound rupture in 3 months after operation were observed. In 6 months after operation, the Vancouver scar scale (VSS) was used to evaluate the scar formation of wounds in 2 groups. Data were statistically analyzed with analysis of variance for repeated measurement, chi-square test, and group t test. Results: The wounds in 2 groups did not heal on 3 and 7 d after operation. The wound healing rate in autologous skin paste group was (29.8±2.5)% and (95.6±4.7)% on 14 and 21 d after operation, which were significantly higher than (25.8±2.9)% and (82.6±8.9)% in conventional treatment group (t=4.3, 5.6, P<0.01). The wound healing time in autologous skin paste group was (21.8±1.4) d, which was significantly shorter than (25.6±2.0) d in conventional treatment group (t=6.24, P<0.01). On 3, 7, 14, 21 d after operation, there were no complications such as subcutaneous effusion and infection in wounds of 2 groups. In 3 months after operation, ulceration occurred in wounds of 2 patients in autologous skin paste group, which was significantly less than 12 patients in conventional treatment group (χ2=11.688, P＜0.01). The wounds with ulceration healed after dressing change. In 6 months after operation, the VSS score of wounds in autologous skin paste group was (9.1±1.1) points, which was significantly lower than (11.3±1.2) points in conventional treatment group (t=-5.75, P＜0.01). Conclusion: The remaining fragments after autologous medium-thickness skin grafting are prepared into skin paste to repair wound of donor site of medium-thickness skin graft can shorten wound healing time, improve wound healing quality, reduce degree of scar hyperplasia, which has a good clinical effect.

Spin fluctuation induced Weyl semimetal state in the paramagnetic phase of EuCd2As2.

Weyl fermions as emergent quasiparticles can arise in Weyl semimetals (WSMs) in which the energy bands are nondegenerate, resulting from inversion or time-reversal symmetry breaking. Nevertheless, experimental evidence for magnetically induced WSMs is scarce. Here, using photoemission spectroscopy, we observe that the degeneracy of Bloch bands is already lifted in the paramagnetic phase of EuCd2As2. We attribute this effect to the itinerant electrons experiencing quasi-static and quasi-long-range ferromagnetic fluctuations. Moreover, the spin-nondegenerate band structure harbors a pair of ideal Weyl nodes near the Fermi level. Hence, we show that long-range magnetic order and the spontaneous breaking of time-reversal symmetry are not essential requirements for WSM states in centrosymmetric systems and that WSM states can emerge in a wider range of condensed matter systems than previously thought.

Dirac nodal surfaces and nodal lines in ZrSiS.

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

Two-dimensional excitons in monolayer transition metal dichalcogenides from radial equation and variational calculations.

Exciton energy spectra of monolayer transition metal dichalcogenides (TMDs) in various dielectric environments are studied with an effective mass model using the Keldysh potential for the screened electron-hole interaction. Two-dimensional (2D) excitons are calculated by solving a radial equation (RE) with a shooting method, using boundary conditions that are derived by applying the asymptotic properties of the Keldysh potential. For any given main quantum number n, the exciton Bohr orbit shrinks as [Formula: see text] becomes larger (m is the orbital quantum number) resulting in increased strength of the electron-hole interaction and a decrease of the exciton energy. Further, both the exciton energy and its effective radius decrease linearly with [Formula: see text]. The screened hydrogen model (SHM) (Olsen et al 2016 Phys. Rev. Lett. 116 056401) is examined by comparing its exciton energy spectra with our RE solutions. While the SHM is found to describe the nonhydrogenic exciton Rydberg series (i.e. the energy's dependence on n) reasonably well, it fails to account for the linear dependence of the exciton energy on the orbital quantum number. The exciton effective radius expression of the SHM can characterize the exciton radius's dependence on n, but it cannot properly describe the exciton radius's dependence on m, which is the cause of the SHM's poor description of the exciton energy's m-dependence. Analytical variational wave-functions are constructed with the 2D hydrogenic wave-functions for a number of strongly bound exciton states, and very close exciton energies and wave-functions are obtained with the variational method and the RE solution (exciton energies are within a 6% of deviation). The variational wave-functions are further applied to study the Stark effects in 2D TMDs, with an analytical expression derived for evaluating the redshift the ground state energy.

Electronic structure of SrSn2As2 near the topological critical point.

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

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

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

Atomically Precise Lateral Modulation of a Two-Dimensional Electron Liquid in Anatase TiO2 Thin Films.

Engineering the electronic band structure of two-dimensional electron liquids (2DELs) confined at the surface or interface of transition metal oxides is key to unlocking their full potential. Here we describe a new approach to tailoring the electronic structure of an oxide surface 2DEL demonstrating the lateral modulation of electronic states with atomic scale precision on an unprecedented length scale comparable to the Fermi wavelength. To this end, we use pulsed laser deposition to grow anatase TiO2 films terminated by a (1 × 4) in-plane surface reconstruction. Employing photostimulated chemical surface doping we induce 2DELs with tunable carrier densities that are confined within a few TiO2 layers below the surface. Subsequent in situ angle-resolved photoemission experiments demonstrate that the (1 × 4) surface reconstruction provides a periodic lateral perturbation of the electron liquid. This causes strong backfolding of the electronic bands, opening of unidirectional gaps and a saddle point singularity in the density of states near the chemical potential.

Topologically Entangled Rashba-Split Shockley States on the Surface of Grey Arsenic.

We discover a pair of spin-polarized surface bands on the (111) face of grey arsenic by using angle-resolved photoemission spectroscopy (ARPES). In the occupied side, the pair resembles typical nearly-free-electron Shockley states observed on noble-metal surfaces. However, pump-probe ARPES reveals that the spin-polarized pair traverses the bulk band gap and that the crossing of the pair at Γ[over ¯] is topologically unavoidable. First-principles calculations well reproduce the bands and their nontrivial topology; the calculations also support that the surface states are of Shockley type because they arise from a band inversion caused by crystal field. The results provide compelling evidence that topological Shockley states are realized on As(111).

Emerging of canine kobuvirus in dogs in China, 2015.

Canine kobuvirus (CaKoV) is a newly emerging virus in dogs, which relates to the diarrhea of dogs. To investigate the CaKoV infection in dog population, fecal samples of dogs were collected from three provinces of China in 2015. The results of genetic analysis based on the complete VP1 gene showed that six CaKoVs isolates in this study were closely related with the Chinese canine originated isolate CH1 (90.6%-91.9% nucleotide identities). The phylogenetic analysis demonstrated that the Chinese isolates clustered into a unique branch compared with isolates from other countries. The present study suggested that the CaKoVs had established infection in Chinese dog population. The systematic epidemiological investigation should be further carried out to evaluate the prevalence of the CaKoV infection in China.

Compensated Semimetal LaSb with Unsaturated Magnetoresistance.

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

Long noncoding RNA FTX inhibits hepatocellular carcinoma proliferation and metastasis by binding MCM2 and miR-374a.

It has long been known that males are more susceptible than females to hepatocellular carcinoma (HCC), but the reason remains elusive. In this study, we investigated the expression and function of the long noncoding RNA FTX (lnc-FTX), an X-inactive-specific transcript (XIST) regulator transcribed from the X chromosome inactivation center, in both HCC and HCC gender disparity. lnc-FTX is expressed at higher levels in female livers than in male livers and is significantly downregulated in HCC tissues compared with normal liver tissues. Patients with higher lnc-FTX expression exhibited longer survival, suggesting that lnc-FTX is a useful prognostic factor for HCC patients. lnc-FTX inhibits HCC cell growth and metastasis both in vitro and in vivo. Mechanistically, lnc-FTX represses Wnt/ß-catenin signaling activity by competitively sponging miR-374a and inhibits HCC cell epithelial-mesenchymal transition and invasion. In addition, lnc-FTX binds to the DNA replication licensing factor MCM2, thereby impeding DNA replication and inhibiting proliferation in HCC cells. In conclusion, these findings suggest that lnc-FTX may act as a tumor suppressor in HCC through physically binding miR-374a and MCM2. It may also be one of the reasons for HCC gender disparity and may potentially contribute to HCC treatment.

The contribution of rare and common variants in 30 genes to risk nicotine dependence.

Genetic and functional studies have revealed that both common and rare variants of several nicotinic acetylcholine receptor subunits are associated with nicotine dependence (ND). In this study, we identified variants in 30 candidate genes including nicotinic receptors in 200 sib pairs selected from the Mid-South Tobacco Family population with equal numbers of African Americans (AAs) and European Americans (EAs). We selected 135 of the rare and common variants and genotyped them in the Mid-South Tobacco Case-Control (MSTCC) population, which consists of 3088 AAs and 1430 EAs. None of the genotyped common variants showed significant association with smoking status (smokers vs non-smokers), Fagerström Test for ND scores or indexed cigarettes per day after Bonferroni correction. Rare variants in NRXN1, CHRNA9, CHRNA2, NTRK2, GABBR2, GRIN3A, DNM1, NRXN2, NRXN3 and ARRB2 were significantly associated with smoking status in the MSTCC AA sample, with weighted sum statistic (WSS) P-values ranging from 2.42 × 10(-3) to 1.31 × 10(-4) after 10(6) phenotype rearrangements. We also observed a significant excess of rare nonsynonymous variants exclusive to EA smokers in NRXN1, CHRNA9, TAS2R38, GRIN3A, DBH, ANKK1/DRD2, NRXN3 and CDH13 with WSS P-values between 3.5 × 10(-5) and 1 × 10(-6). Variants rs142807401 (A432T) and rs139982841 (A452V) in CHRNA9 and variants V132L, V389L, rs34755188 (R480H) and rs75981117 (N549S) in GRIN3A are of particular interest because they are found in both the AA and EA samples. A significant aggregate contribution of rare and common coding variants in CHRNA9 to the risk for ND (SKAT-C: P=0.0012) was detected by applying the combined sum test in MSTCC EAs. Together, our results indicate that rare variants alone or combined with common variants in a subset of 30 biological candidate genes contribute substantially to the risk of ND.

Micro-computed tomography evaluation of the removal of calcium hydroxide medicament from C-shaped root canals of mandibular second molars.

AIM: To use micro-computed tomography (µ-CT) to evaluate the amount of calcium hydroxide [Ca(OH)2 ] remaining in the C-shaped root canals of mandibular second molars after attempting to remove it with passive ultrasonic and sonic irrigation. METHODOLOGY: Thirty mandibular second molars, 15 in C1 and 15 in C2 configurations as first identified by µ-CT, were divided into three groups (five C1 and five C2 in each group) for the three irrigation methods. All teeth were prepared to ProTaper Universal F2 and filled with Ca(OH)2 paste. The Ca(OH)2 was removed with F2 files and irrigation without agitation or with agitation using either EndoActivator or ultrasonics. µ-CT was used to measure the initial amount of Ca(OH)2 present. After removal of Ca(OH)2, µ-CT imaging was used to assess the percentage of volume of residual Ca(OH)2 in the canal. Data were analysed using one-way anova test. RESULTS: There was no significant difference in the mean volume of the root canal systems after instrumentation amongst the three groups. The three irrigation techniques left 2-17% of Ca(OH)2 in the root canals after removal. The mean volume of the remaining Ca(OH)2 was higher in the group without agitation than in the groups with sonic or ultrasonic agitation (P < 0.05). In the apical third, 68% of the canal space remained occupied by Ca(OH)2 when no agitation was used, whereas 28% and 31% remained filled by Ca(OH)2 in the EndoActivator and ultrasonic groups, respectively. There was no significant difference in the amount of residual Ca(OH)2 between the EndoActivator and ultrasonic groups. The proportion of remaining Ca(OH)2 in the apical canals was higher than in the middle and coronal canals in all groups (P < 0.05). CONCLUSIONS: A considerable proportion of the apical canal space remained filled with Ca(OH)2 in the C-shaped root canals after instrumentation and conventional needle irrigation. Although combining rotary instrumentation and irrigation with sonic or ultrasonic agitation reduced the amount of residual Ca(OH)2 in the C-shaped root canals, the large amount of calcium hydroxide in the critical apical area remains a concern. Alternative strategies should be considered in medication of the apical canal in C-shaped teeth.

Screening and analyzing genes associated with Amur tiger placental development.

The Amur tiger is a unique endangered species in the world, and thus, protection of its genetic resources is extremely important. In this study, an Amur tiger placenta cDNA library was constructed using the SMART cDNA Library Construction kit. A total of 508 colonies were sequenced, in which 205 (76%) genes were annotated and mapped to 74 KEGG pathways, including 29 metabolism, 29 genetic information processing, 4 environmental information processing, 7 cell motility, and 5 organismal system pathways. Additionally, PLAC8, PEG10 and IGF-II were identified after screening genes from the expressed sequence tags, and they were associated with placental development. These findings could lay the foundation for future functional genomic studies of the Amur tiger.

Development of an indirect ELISA with epitope on nonstructural protein of Muscovy duck parvovirus for differentiating between infected and vaccinated Muscovy ducks.

UNLABELLED: The aim of this study was to develop an indirect enzyme-linked immunosorbent assay (i-ELISA) based on epitope AA503-509 (RANEPKE), which is on nonstructural protein of Muscovy duck parvovirus (MDPV). Sera (100) from negative and vaccinated Muscovy ducks were compared with infected sera (240) to establish the cut-off value of this i-ELISA. There was a significant difference between the positive and negative populations (P < 0·05). The adoption of this positive-negative threshold value for this i-ELISA assay resulted in specificity of 98·0%. This i-ELISA could be used as a diagnostic tool for differentiating infected Muscovy ducks from Muscovy ducks vaccinated with inactivated virus. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, we developed an i-ELISA based on epitope AA503-509 (RANEPKE), which is on nonstructural protein of MDPV. This i-ELISA could be used as a diagnostic tool for differentiating infected Muscovy ducks from Muscovy ducks vaccinated with inactivated virus.

The role of minority geographic distribution in waiting time for deceased donor kidney transplantation.

In the US, African Americans and other minority groups have longer wait times to deceased donor kidney transplantation than Caucasians. To date, the role of geographic distribution of racial and ethnic groups as a determinant of wait times has not been fully elucidated. Using the Scientific Registry of Transplant Recipients database, all registrants for kidney transplant between 2004 and 2007 (n=126,094) were analyzed from time of waitlisting until nonzero antigen mismatched deceased donor kidney transplant. Nationally, deceased donor transplantation occurred at a lower rate for African Americans (hazard ratio [HR] 0.85, confidence interval [CI] 0.83-0.87), Hispanics (HR 0.68, CI 0.66-0.70), Asians/Pacific Islanders (HR 0.77, CI 0.73-0.80) and Other minority groups (HR 0.74, CI 0.69-0.81) compared to Caucasians. Multivariate modeling for age, gender, cause of end-stage renal disease, ABO type, panel reactive antibody, HLA-DR frequency, expanded criteria donor status and prior kidney donation only partially accounted for this difference. Adjusting for these variables and organ procurement organization of listing, African Americans (HR 1.03, CI 1.00-1.06), Hispanics (HR 1.15, CI 1.10-1.19), Asians/Pacific Islanders (HR 1.36, CI 1.30-1.43) and Other minority groups (HR 1.00, CI 0.92-1.09) were transplanted at similar or higher rates than Caucasians. Our findings show that geographic location of waitlisted candidates is the most important contributor to racial disparities in waiting times for deceased donor kidney transplantation.