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1.
Inorg Chem ; 63(37): 17026-17031, 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39230575

RESUMO

Lanthanides (Ln) are notoriously difficult to intercalate into graphite. We investigated the possibility of using Na to catalyze the formation of Ln-intercalated graphite and successfully synthesized LnC6 (Ln = Sm, Eu, and Yb) significantly rapidly in high yields. The synthesis process involves the formation of the reaction intermediate NaCx, through the mixing of Na and C, which subsequently reacts with Ln upon heating to form LnC6. Well-sintered LnC6 pellets with low residual Na concentrations (Ln:Na ≈ 98:2) were fabricated by the two-step method. The pellets enabled the evaluation of LnC6 by powder X-ray diffraction and electrical resistivity measurements. This study highlights the versatility of the Na-catalyzed method and lays the foundation for the rapid mass production of LnC6, with potential applications in superconducting and rechargeable battery materials.

2.
Surg Endosc ; 38(3): 1222-1229, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38092971

RESUMO

BACKGROUND: Currently, widely used robotic surgical systems do not provide force feedback. This study aimed to evaluate the impact and benefits of a force feedback function on the suturing procedure. METHODS: Twenty surgeons were recruited and divided into young (Y-group, n = 11) and senior (S-group, n = 9) groups, based on their years of surgical experience. The effect of the force feedback function on suturing quality was evaluated using an objective assessment system (A-LAP mini, Kyoto Kagaku Co., Ltd., Kyoto, Japan). Each participant completed the suturing task on intestinal model sheets with the robotic contact force feedback on and off. The task accomplishment time (s), maximal force (Newton, N) applied to the robotic forceps, and quality of suturing (assessed by A-LAP mini) were recorded as performance parameters. RESULTS: In total, the maximal force applied to the robotic forceps was significantly decreased with the robotic force feedback switched on (median [interquartile range]: 2.8 N (2.3-3.2)) as compared with when the feedback was switched off (3.4 N (2.7-4.0), P < 0.001). The contact force feedback function did not affect the objectively assessed suturing score (18 points (17.7-19.0) versus 18 points (17.0-19.0), P = 0.421). The contact force feedback function slightly shortened the task accomplishment time in the Y-group (552.5 s (466.5-832) versus 605.5 s (476.2-689.7), P = 0.851) but not in the S-group (566 s (440.2-703.5) versus 470.5 s (419.7-560.2), P = 0.164). CONCLUSIONS: With the contact force feedback function, the suturing task was completed with a smaller maximal force, while maintaining the quality of suturing. Because the benefits are more apparent in young surgeons, robots with the contact force feedback function will facilitate the educational process in novice surgeons.


Assuntos
Procedimentos Cirúrgicos Robóticos , Robótica , Cirurgiões , Humanos , Robótica/métodos , Retroalimentação , Procedimentos Neurocirúrgicos , Instrumentos Cirúrgicos , Competência Clínica , Técnicas de Sutura
3.
Proc Natl Acad Sci U S A ; 118(37)2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34493664

RESUMO

Magnetic superconductors are specific materials exhibiting two antagonistic phenomena, superconductivity and magnetism, whose mutual interaction induces various emergent phenomena, such as the reentrant superconducting transition associated with the suppression of superconductivity around the magnetic transition temperature (T m), highlighting the impact of magnetism on superconductivity. In this study, we report the experimental observation of the ferromagnetic order induced by superconducting vortices in the high-critical-temperature (high-T c) magnetic superconductor EuRbFe4As4 Although the ground state of the Eu2+ moments in EuRbFe4As4 is helimagnetism below T m, neutron diffraction and magnetization experiments show a ferromagnetic hysteresis of the Eu2+ spin alignment. We demonstrate that the direction of the Eu2+ moments is dominated by the distribution of pinned vortices based on the critical state model. Moreover, we demonstrate the manipulation of spin texture by controlling the direction of superconducting vortices, which can help realize spin manipulation devices using magnetic superconductors.

4.
Surg Today ; 54(8): 817-828, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38829562

RESUMO

Telesurgery is expected to improve medical access in areas with limited resources, facilitate the rapid dissemination of new surgical procedures, and advance surgical education. While previously hindered by communication delays and costs, recent advancements in information technology and the emergence of new surgical robots have created an environment conducive to societal implementation. In Japan, the legal framework established in 2019 allows for remote surgical support under the supervision of an actual surgeon. The Japan Surgical Society led a collaborative effort, involving various stakeholders, to conduct social verification experiments using telesurgery, resulting in the development of a Japanese version of the "Telesurgery Guidelines" in June 2022. These guidelines outline requirements for medical teams, communication environments, robotic systems, and security measures for communication lines, as well as responsibility allocation, cost burden, and the handling of adverse events during telesurgery. In addition, they address telementoring and full telesurgery. The guidelines are expected to be revised as needed, based on the utilization of telesurgery, advancements in surgical robots, and improvements in information technology.


Assuntos
Sociedades Médicas , Telemedicina , Japão , Humanos , Procedimentos Cirúrgicos Robóticos/normas , Equipe de Assistência ao Paciente , Tecnologia da Informação , Guias de Prática Clínica como Assunto , Cirurgia Geral/educação
5.
Surg Today ; 54(4): 375-381, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37653350

RESUMO

PURPOSE: To verify the usefulness of haptic feedback in telesurgery and improve the safety of telerobotic surgery. METHODS: The surgeon's console was installed at two sites (Fukuoka and Beppu; 140 km apart), and the patient cart was installed in Fukuoka. During the experiment, the surgeon was blinded to the haptic feedback levels and asked to grasp the intestinal tract in an animal model. The surgeon then performed the tasks at each location. RESULTS: No marked differences in task accuracy or average grasping force were observed between the surgeon locations. However, the average task completion time was significantly longer, and the system usability scale (SUS) was significantly lower rating for remote operations than for local ones. No marked differences in task accuracy or task completion time were observed between the haptic feedback levels. However, with haptic feedback, the organ was grasped with a significantly weaker force than that without it. Furthermore, with haptic feedback, experienced surgeons in robotic surgery tended to perform an equivalent task with weaker grasping forces than inexperienced surgeons. CONCLUSION: The haptic feedback function is a tool that allows the surgeon to perform surgery with an appropriate grasping force, both on site and remotely. Improved safety is necessary in telesurgery; haptic feedback will thus be an essential technology in robotic telesurgery going forward.


Assuntos
Procedimentos Cirúrgicos Robóticos , Robótica , Cirurgiões , Animais , Humanos , Retroalimentação , Tecnologia Háptica
6.
Surg Endosc ; 37(12): 9676-9683, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37935920

RESUMO

BACKGROUND: In telementoring, differences in teaching methods affect local surgeons' comprehension. Because the object to be operated on is a three-dimensional (3D) structure, voice or 2D annotation may not be sufficient to convey the instructor's intention. In this study, we examined the usefulness of telementoring using 3D drawing annotations in robotic surgery. METHODS: Kyushu University and Beppu Hospital are located 140 km apart, and the study was conducted using a Saroa™ surgical robot by RIVERFIELD Inc. using a commercial guarantee network on optical fiber. Twenty medical students performed vertical mattress suturing using a swine intestinal tract under surgical guidance at the Center for Advanced Medical Innovation Kyushu University. Surgical guidance was provided by Beppu Hospital using voice, 2D, and 3D drawing annotations. All robot operations were performed using 3D images, and only the annotations were independently switched between voice and 2D and 3D images. The operation time, needle movement, and performance were also evaluated. RESULTS: The 3D annotation group tended to have a shorter working time than the control group (25.6 ± 63.2 vs. - 36.7 ± 65.4 min, P = 0.06). The 3D annotation group had fewer retries than the control group (1.3 ± 1.7 vs. - 1.1 ± 0.7, P = 0.006), and there was a tendency for fewer needle drops (0.4 ± 0.7 vs. - 0.5 ± 0.9, P = 0.06). The 3D annotation group scored significantly higher than the control group on the Global Evaluate Assessment of Robot Skills (16.8 ± 2.0 vs. 22.8 ± 2.4, P = 0.04). The 3D annotation group also scored higher than the voice (13.4 ± 1.2) and 2D annotation (16.2 ± 1.8) groups (3D vs. voice: P = 0.03, 3D vs. 2D: P = 0.03). CONCLUSION: Telementoring using 3D drawing annotation was shown to provide good comprehension and a smooth operation for local surgeons.


Assuntos
Procedimentos Cirúrgicos Robóticos , Cirurgiões , Humanos , Animais , Suínos , Procedimentos Cirúrgicos Robóticos/métodos , Intestinos , Imageamento Tridimensional , Duração da Cirurgia
7.
Surg Endosc ; 37(8): 6071-6078, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37126192

RESUMO

BACKGROUND: Although several studies on telesurgery have been reported globally, a clinically applicable technique has not yet been developed. As part of a telesurgical study series conducted by the Japan Surgical Society, this study describes the first application of a double-surgeon cockpit system to telesurgery. METHODS: Surgeon cockpits were installed at a local site and a remote site 140 km away. Three healthy pigs weighing between 26 and 29 kg were selected for surgery. Non-specialized surgeons performed emergency hemostasis, cholecystectomy, and renal vein ligation with remote assistance using the double-surgeon cockpits and specialized surgeons performed actual telesurgery. Additionally, the impact of adding internet protocol security (IPsec) encryption to the internet protocol-virtual private network (IP-VPN) line on communication was evaluated to address clinical security concerns. RESULTS: The average time required for remote emergency hemostasis with the double-surgeon cockpit system was 10.64 s. A non-specialized surgeon could safely perform cholecystectomy or renal vein ligation with remote assistance. Global Evaluative Assessment of Robotic Skills and System Usability Scale scores were higher for telesurgical support-assisted surgery by a non-specialized surgeon using the double-surgeon cockpits than for telesurgery performed by a specialized surgeon without the double-cockpit system. Adding IPsec encryption to the IP-VPN did not have a significant impact on communication. CONCLUSION: Telesurgical support through our double-surgeon cockpit system is feasible as first step toward clinical telesurgery.


Assuntos
Colecistectomia , Telemedicina , Telemedicina/métodos , Humanos , Suínos , Cirurgiões , Animais
8.
Inorg Chem ; 61(31): 12149-12154, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35880851

RESUMO

Enriching the material variation often contributes to the progress of materials science. We have discovered for the first time antiperovskite arsenide SrPd3As and revealed a hidden structural and superconducting phase in Sr(Pd1-xPtx)3As. The Pd-rich samples (0 ≤ x ≤ 0.2) had the same noncentrosymmetric (NCS) tetragonal structure (a space group of I41md) as SrPd3P. For the samples with 0.3 ≤ x ≤ 0.7, a centrosymmetric (CS) tetragonal structure (P4/nmm) identical to that of SrPt3P was found to appear, accompanied by superconductivity at a transition temperature (Tc) up to 3.7 K. In the samples synthesized with Pt-rich nominal compositions (0.8 ≤ x ≤ 1.0), Sr2(Pd,Pt)8-yAs1+y with an intergrowth structure (CS-orthorhombic with Cmcm) was crystallized. The phase diagram obtained for Sr(Pd,Pt)3As was analogous to that of (Ca,Sr)Pd3P in which superconductivity (Tc ≥ 2 K) occurred in the CS phases induced by substitutions to the NCS phases. This study indicates the potential for further material variation expansion and the importance of elemental substitutions to reveal hidden phases in related antiperovskites.

9.
Surg Today ; 52(4): 705-714, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34668052

RESUMO

PURPOSE: In recent years, the expectations for telesurgery have grown with the development of robot-assisted surgical technology and advances in communication technology. To verify the feasibility of the social implementation of telesurgery, we evaluated the communication integrity, availability, and communication delay of robotic surgery by remote control under different communication conditions of commercial lines. METHODS: A commercial line was used to connect hospitals 150 km apart. We had prepared guaranteed-type lines (1Gbps, 10Mbps, 5Mbps) and best effort-type lines. Two types of robotic teleoperations were performed, and we evaluated the round-trip time (RTT) of communication, packet loss, and glass-to-glass time. RESULTS: The communication delay was 4 ms for the guaranteed-type line and 10 ms for the best effort-type line. Packet loss occurred on the 5 Mbps guaranteed-type line. The mean glass-to-glass time was 92 ms for the guaranteed-type line and 95 ms for the best effort-type line. There was no significant difference in the number of errors in the task according to the type of line or the bandwidth speed. CONCLUSIONS: The social implementation of telesurgery using the currently available commercial communication network is feasible.


Assuntos
Procedimentos Cirúrgicos Robóticos , Robótica , Telemedicina , Humanos , Japão
10.
Physiol Genomics ; 53(7): 285-294, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34097531

RESUMO

We investigated changes in rumen fermentation, peripheral blood metabolites and hormones, and hepatic transcriptomic dynamics in Holstein cows with and those without subacute ruminal acidosis (SARA) during the periparturient period. Sixteen multiparous Holstein cows were categorized in the SARA (n = 8) or non-SARA (n = 8) groups depending on whether they developed SARA during the 2 wk after parturition. Reticulo-ruminal pH was measured continuously throughout the study. Rumen fluid, blood, and liver tissue samples were collected at 3 wk prepartum and 2 and 6 wk postpartum, with an additional blood sample collected at 0 and 4 wk postpartum. The 1-h mean pH was depressed postpartum in both groups, whereas depression was more severe in the SARA group simultaneously with significantly longer duration of time (for pH <5.6 and 5.8). Significant expression of differentially expressed genes in liver tissue (DEGs; false discovery rate corrected P < 0.1) were identified only in the non-SARA group and were further analyzed by Ingenuity Pathway Analysis software. Among the top expressed DEGs, the hepatic genes encoding lipid and cholesterol secretion (APOA1, APOA4, and G0S2) and gluconeogenesis (PC, G6PC, and PCK1) were upregulated postpartum. In silico analysis revealed the significant postpartum activation of upstream regulators, such as INSR, PPARG, and PPARGC1A. These results suggested that hepatic transcriptomic responsiveness to postpartum metabolic load and hormones were likely discouraged in cows with SARA when compared with the significant activation of genes and signaling pathways for adequate metabolic adaption to postpartum high-grain diet feeding in Holstein cows without SARA.


Assuntos
Acidose/veterinária , Fígado/fisiologia , Rúmen/metabolismo , Gastropatias/veterinária , Acidose/metabolismo , Animais , Peso Corporal , Bovinos , Doenças dos Bovinos/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Hormônios/sangue , Concentração de Íons de Hidrogênio , Parto , Período Pós-Parto , Rúmen/fisiopatologia , Gastropatias/metabolismo
11.
Inorg Chem ; 60(23): 18017-18023, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34779197

RESUMO

Antiperovskites are a promising candidate structure for the exploration of new materials. We discovered an antiperovskite phosphide, LaPd3P, following our recent synthesis of APd3P (A = Ca, Sr, Ba). While APd3P and (Ca,Sr)Pd3P were found to be tetragonal or orthorhombic systems, LaPd3P is a new prototype cubic system (a = 9.0317(1) Å) with a noncentrosymmetric space group (I4̅3m). LaPd3P exhibited superconductivity with a transition temperature (Tc) of 0.28 K. The upper critical field, Debye temperature, and Sommerfeld constant (γ) were determined to be 0.305(8) kOe, 267(1) K, and 6.06(4) mJ mol-1 K-2 f.u.-1, respectively. We performed first-principles electronic band structure calculations for LaPd3P and compared the theoretical and experimental results. The calculated Sommerfeld constant (2.24 mJ mol-1 K-2 f.u.-1) was much smaller than the experimental value of γ because the Fermi energy (EF) was located slightly below the density of states (DOS) pseudogap. This difference was explained by the increase in the DOS at EF due to the approximately 5 atom % La deficiency (hole doping) in the sample. The observed Tc value was much lower than that estimated using the Bardeen-Cooper-Schrieffer equation. To explain the discrepancy, we examined the possibility of an unconventional superconductivity in LaPd3P arising from the lack of space inversion symmetry.

12.
Phys Chem Chem Phys ; 23(35): 19827-19833, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34525149

RESUMO

We investigated the defect structures of polycrystalline CaKFe4As4 (CaK1144) superconductors by scanning transmission electron microscopy (STEM). The STEM studies revealed the presence of a one-layer CaFe2As2 (∼1 nm size) defect along the ab-plane, as observed in single crystalline CaK1144. Step-like CaFe2As2 defects are also observed. These nanoscale defects generate fine-sized stacking faults, a lattice mismatch, and stress field defects in the matrix of CaK1144 owing to the different sizes. Correlation of the defects in polycrystalline and single crystalline samples suggests that the defects type and their density depend on the synthesis conditions. A self-field critical current density (Jc) of 15.2 kA cm-2 was obtained at 5 K, and the curves were sustained above 30 K with a considerable Jc value of 1.4 kA cm-2. We investigated the relationship between the observed intrinsic defects and the behavior of the field dependence of Jc. The intrinsically intergrown planar defects, even in polycrystalline samples, are expected to be advantageous for various high-field applications of bulk CaK1144 superconductors.

13.
BMC Vet Res ; 17(1): 156, 2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33849520

RESUMO

BACKGROUND: The type 2 highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) has spread throughout countries of southeast Asia, where it has caused severe economic losses. Even countries presently free of PRRSV are at high risk for infection and spread of this virus. Some of these countries, including Japan, have broad epidemics of the local type 2 PRRSV, creating chronic pathogenicity in the domestic pig population. The present study aimed to evaluate the protective efficacy of immunity by infection with a Japanese field isolate, EDRD1, against heterologous challenge with a Vietnamese HP-PRRSV field strain. To this end, four groups of PRRSV-negative crossbreed piglets were used for a challenge study. Groups 1 and 2 were inoculated with EDRD1 via the intranasal route. After 26 days, Groups 2 and 3 were inoculated with HP-PRRSV via the same route. Group 4 served as an uninfected control. Blood and oral fluid samples were taken every 3-4 days after HP-PRRSV challenge; on day 16 post-challenge, all pigs were euthanized, and examined pathologically. RESULTS: The nucleotide sequence analysis of nonstructural protein 2 gene of EDRD1 and comparison with Vietnamese HP-PRRSV showed that the 39 amino acid deletion sites of EDRD1 was nearly in the same region as the 29 amino acid deletion sites of HP-PRRSV. Immunity conferred by inoculation with EDRD1 dramatically reduced viral load in the sera and tissues besides viral shedding (Group 2) compared with those in pigs infected only with HP-PRRSV (Group 3). The clinical signs and rectal temperature were significantly reduced, and the average daily weight gain was significantly improved in the EDRD1-inoculated pigs (Group 2) compared with the Group 3 pigs. Notably, no viral RNA was detected in various organs of the Group 2 pigs 16 days post-infection with HP-PRRSV, except in one pig. Therefore, the immunity induced by EDRD1 and its genetically close field isolates may play a role in reducing viremia caused by HP-PRRSV. CONCLUSIONS: The results of the present study demonstrate that pigs are highly protected against heterologous Vietnamese HP-PRRSV challenge by immunity against a Japanese local strain, EDRD1.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Vírus da Síndrome Respiratória e Reprodutiva Suína/patogenicidade , Administração Intranasal/veterinária , Animais , Anticorpos Antivirais/sangue , Síndrome Respiratória e Reprodutiva Suína/patologia , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Sus scrofa , Suínos , Carga Viral/veterinária , Proteínas não Estruturais Virais/genética , Viremia/veterinária
14.
Inorg Chem ; 59(17): 12397-12403, 2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32845611

RESUMO

In this study, we succeeded in synthesizing new antiperovskite phosphides MPd3P (M = Ca, Sr, Ba) and discovered the appearance of a superconducting phase (0.17 ≤ x ≤ 0.55) in a solid solution (Ca1-xSrx)Pd3P. Three perovskite-related crystal structures were identified in (Ca1-xSrx)Pd3P, and a phase diagram was built on the basis of experimental results. The first phase transition from centrosymmetric (Pnma) to noncentrosymmetric orthorhombic (Aba2) occurred in CaPd3P near room temperature. The phase transition temperature decreased as Ca2+ was replaced with a larger-sized isovalent Sr2+. Bulk superconductivity at a critical temperature (Tc) of approximately 3.5 K was observed in a range of x = 0.17-0.55; this was associated with the centrosymmetric orthorhombic phase. Thereafter, a noncentrosymmetric tetragonal phase (I41md) remained stable for 0.6 ≤ x ≤ 1.0, and superconductivity was significantly suppressed as samples with x = 0.75 and 1.0 showed Tc values as low as 0.32 K and 57 mK, respectively. For further substitution with a larger-sized isovalent Ba2+, namely, (Sr1-yBay)Pd3P, the tetragonal phase continued throughout the composition range. BaPd3P no longer showed superconductivity down to 20 mK. Since the inversion symmetry of structure and superconductivity can be precisely controlled in (Ca1-xSrx)Pd3P, this material may offer a unique opportunity to study the relationship between inversion symmetry and superconductivity.

15.
Inorg Chem ; 59(19): 14290-14295, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-32921044

RESUMO

It is generally difficult to quantify the amount of light elements in materials because of their low X-ray-scattering power, as this means that they cannot be easily estimated via X-ray analyses. Meanwhile, the recently reported layered superconductor, Sc20C8-xBxC20, requires a small amount of boron, which is a light element, for its structural stability. In this context, here, we quantitatively evaluate the optimal x value using both experimental and computational approaches. Using the high-pressure synthesis approach, which can maintain the starting composition even after sintering, we obtain the Sc20(C,B)8C20 phase by the reaction of the previously reported Sc15C19 and B (Sc15ByC19). Our experiments demonstrate that an increase in y values promotes the phase formation of the Sc20(C,B)8C20 structure; however, there appears to be an upper limit to the nominal y value to form this phase. The maximum critical temperature (Tc = 7.6 K) is found to correspond with the actual x value of x ≈ 5 under the assumption that the sample with the same Tc as the reported value (7.7 K) possesses the optimal x amount. Moreover, we construct the energy convex hull diagram by calculating the formation enthalpy based on first principles. Our computational results indicate that the composition of Sc20C4B4C20 (x = 4) is the most thermodynamically stable, which is reasonably consistent with the experimentally obtained value.

16.
J Dairy Sci ; 103(5): 4702-4716, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32171513

RESUMO

The authors have elected to retract this paper in accordance with the following points. The article as written contains misleading information and omits important details. Cows in this study were assigned to groups based on the current definition of subacute ruminal acidosis; they were housed on two different farms and fed two different sets of rations in this study. However, multiple farms were not described in the materials and methods and this was not accounted for in the statistical analysis as published. The diets shown in Table 1 were not actually fed to animals; rather, the proportions of ingredients listed represent an average of the two farms housing the cows. The authors regret the errors.


Assuntos
Acidose/veterinária , Bactérias/isolamento & purificação , Doenças dos Bovinos/microbiologia , Ácidos Graxos Voláteis/análise , Microbioma Gastrointestinal , Acidose/metabolismo , Acidose/microbiologia , Animais , Bactérias/genética , Bovinos , Doenças dos Bovinos/metabolismo , Dieta/veterinária , Feminino , Fermentação , Concentração de Íons de Hidrogênio , Parto , Gravidez , Prevotella/genética , Prevotella/isolamento & purificação , Rúmen/metabolismo , Rúmen/microbiologia
17.
Inorg Chem ; 58(22): 15629-15636, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31661255

RESUMO

The discovery of nearly room-temperature superconductivity in superhydrides has motivated further materials research for conventional superconductors. To realize the moderately high critical temperature (Tc) in materials containing light elements, we explored new superconducting phases in a scandium borocarbide system. Here, we report the observation of superconductivity in a new ternary Sc-B-C compound. The crystal structure, which was determined through a Rietveld analysis, belongs to tetragonal space group P4/ncc. By complementarily using the density functional theory calculations, a chemical formula of the compound was found to be expressed as Sc20C8-xBxC20 (x = 1 or 2). Interestingly, a small amount of B is essential to stabilize the present structure. Our experiments revealed the typical type-II superconductivity at Tc = 7.7 K. Additionally, we calculated the density of states within a first-principles approach and found that the contribution of the Sc-3d orbital was mainly responsible for the superconductivity.

18.
J Foot Ankle Surg ; 58(3): 596-598, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30744918

RESUMO

Bony mallet injury of the hallux is uncommon. In the few reports of this injury, authors have described surgical treatments such as closed reduction with percutaneous pinning and open surgical fixation with Kirschner wires or a suture anchor. However, the appropriate surgical management for this injury remains controversial. In this article, we describe a case of bony mallet injury of the hallux repaired with the modified extension block techniqueusing 3 Kirschner wires. This method is an effective and simple treatment to allow anatomic reduction of the displaced articular fracture fragment without incision, residual hardware, or the complications associated with open surgical treatment.


Assuntos
Fixação Interna de Fraturas/métodos , Fratura Avulsão/cirurgia , Hallux/lesões , Hallux/cirurgia , Falanges dos Dedos do Pé/lesões , Falanges dos Dedos do Pé/cirurgia , Adulto , Fios Ortopédicos , Fratura Avulsão/diagnóstico por imagem , Hallux/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Masculino , Falanges dos Dedos do Pé/diagnóstico por imagem , Tomografia Computadorizada por Raios X
19.
J Am Chem Soc ; 140(1): 369-374, 2018 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-29280633

RESUMO

(La0.5-xNa0.5+x)Fe2As2 ((La,Na)122) is an interesting system in the sense that either electrons (x < 0) or holes (x > 0) can be doped into the Fe2As2 layers, simply by changing the composition value x. However, only nonbulk superconducting samples (single crystals) with x = 0.1 have been synthesized to date. Here, we successfully synthesize polycrystalline samples with a wide hole-doping composition range of 0 ≤ x ≤ 0.35 via a conventional solid-state reaction, by tuning the reaction temperature according to x. The parent compound, (La0.5Na0.5)Fe2As2 (x = 0), is a nonsuperconductor with a resistivity anomaly at 130 K due to structural and antiferromagnetic transitions. We find that the temperature of the resistivity anomaly decreases with increasing x and that bulk superconductivity emerges for 0.15 ≤ x ≤ 0.35. The maximum transition temperature is 27.0 K, for x = 0.3. An electronic phase diagram for the hole-doping side is constructed. However, electron-doped samples (x < 0) cannot be synthesized; thus, the other half of the electronic phase diagram of (La,Na)122 requires resolution to study the electron-hole symmetry in Fe-based superconductors.

20.
Chemistry ; 24(60): 16113-16125, 2018 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-30285295

RESUMO

5,12-Diamino-substituted tetracenes with various N-substituents have been prepared, and their molecular structural changes upon oxidation have been evaluated in association with their electronic structures. The N-substituents influence both the electronic and molecular structures of the oxidized species of 5,12-diaminotetracenes. The tetracene moiety of 5,12-bis(N,N-dianisylamino)tetracene retained its planarity during the course of two successive one-electron oxidations, whereas 5,12-bis(N,N-dimethylamino)tetracene and 5,12-bis(N-anisyl-N-methylamino)tetracene underwent substantial structural changes into butterfly like structures through a simultaneous two-electron oxidation process. The molecular structures in the oxidized states were closely related to the nature of the highest occupied orbitals, which were characterized by the extent of mixing between the fragment orbitals for the teracene moiety and the substituted amino groups in 5,12-diaminotetracenes. As a consequence, the present work revealed that the extent of folding deformation of the acene moiety in the oxidized diaminoacenes could be fine-tuned by varying the N-substituents.

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