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Repairing defects in titanium alloy components is economically justified due to their high cost. In this work, Ti–6Al–4V samples with large area hole defects are repaired by transient liquid-phase sintering. The microstructure and tensile properties after repair have been investigated. The factors of different base powder morphology and the ratio of braze metal are also studied. The results show that by using spherical Ti64 alloy powder with 40 wt% TiZrCuNi braze alloy powder, an overall repair effect with high-density repair zone and good interface combination can be obtained at 960 °C for 3 h. The tensile strength of the as-repaired exceeds that of the matrix, but the elongation is lower than that of the matrix. Finally, the repair experiment conducted at various angles demonstrates this technique's strong practical feasibility.

The R programming language that provides a variety of statistical calculation functions is considered to be one of the programming languages most suitable for artificial intelligence.The correctness of the language implementation is a prerequisite for the correctness of the programs developed with such a language.However,there are inevitably many defects in the R programming language.This paper conducts an empirical study on defects in the R programming language and its core packages.By analyzing 7020 issues,we find that:1) Among all the 35 versions involved in these defects,there are the most defects in R 3.1.2,R 3.0.2 and R 3.5.0,and these defects are primarily distributed in a few components such as Documentation,Graphics,Language.2) The components with higher overall defect priority include Startup,Installation and Analyses,and the components with higher overall defect severity include I/O,Installation and Accuracy.There is a significant intermediate correlation between the priority and severity of the defects.3) About 78% of defects could be repaired within one year.4) Semantic faults are the most frequent root cause of defects,in which the “missing feature” and “processing” are more than others.These findings reveal some laws of defects in the R programming language and its core packages.It can assist developers of the R programming language in improving their development quality,assist maintainers of the R programming language in detecting and repairing defects more effectively,and suggest users of the R programming language evade potential risks.

Abstract Objective To describe the clinical outcome and physical condition of patients with locally advanced breast cancer (LABC) who received neoadjuvant chemotherapy followed by mastectomy and latissimus dorsi myocutaneous flap repair. Methods A retrospective review of 142 patients with locally advanced breast cancer was selected from 1156 breast cancer patients in the South and North areas of The Affiliated Calmette Hospital of Kunming Medical University between May 2008 and December 2018. Results All participants (n = 142) were women aged 40–55 years (average age 47.35 ± 0.43 years) who received neoadjuvant chemotherapy followed by mastectomy and latissimus dorsi flap repair. The median follow-up period was 16 months (range 12–24 months). For stage of disease, there were 19 cases (13%) in stage IIB, 31 cases (22%) in stage IIIA, 39 cases (28%) in stage IIIB, and 53 cases (37%) in stage IIIC, which were statistically significant with the physical condition of patients (≤ 0.001). Neoadjuvant chemotherapy was administered to shrink the tumors, and an average tumor size decrease from 10.05 ± 1.59 cm × (8.07 ± 1.54) cm to 6.11 ± 1.72 cm × (3.91 ± 1.52) cm (P < 0.001) was considered statistically significant. A t test was used for the ECOG score statistics, and the results showed that the scores were statistically significant (≤ 0.001) before and after neoadjuvant chemotherapy and after surgery. Conclusions Neoadjuvant chemotherapy is an accepted treatment option for patients with locally advanced breast cancer, and the use of a latissimus dorsi musculocutaneous flap for post-mastectomy reconstruction may improve the patients’ physical condition. Our results indicated that this strategy was safe and feasible.

Pd membranes can play an important role in H2 separation and purification for the development of sustainable and renewable energies. By supporting on porous substrates, Pd layer thickness can be reduced to several micrometers, thus improving the H2 permeance by several orders of magnitude. However, the supported thin Pd membranes are concomitant with pinhole formation due to either fabrication (e.g., electroless-plating) or thermal treatment, which exist as a remarkable challenge for its widespread applications. This study presents a novel and facile approach for self-repair of Pd membrane defects by immersing the stainless-steel supported Pd membranes in PdCl2 solution. Three membranes were deliberately selected with a low selectivity of 152–1687 (400 ​°C, 0.1Mpa), for which disproportionation reactions between Pd2+ and Fe/Cr/Ni at the defect sites spontaneously occur leading to the formation of Pd particles at the exact point of defects. This self-repair process can be enhanced when applying a high pressure of 30–50 ​bar in the PdCl2 solution for 30 ​min, by overcoming the capillary resistance and penetrating through the pinholes. Interestingly, densely distributed hillocks were observed on the membrane surface probably due to reduction of PdCl2 under following H2 treatment, thus increasing the H2 permeance with a higher effective surface area. The H2/N2 selectivity can be improved by more than one order of magnitude (in the best case from 1687 to 8768) and a long-term stability test of 300 ​h was achieved for the repaired membranes, corroborating the application potential of this approach.

Tongue repair after radical surgical removal of malignant tumors with subsequent rehabilitation of patients and their return to normal life and work has been a challenging issue for decades.This review aims to give an up to date summary of existing literature on different methods of tongue repair in cancer patients depending on the type of defect. We describe advantages and disadvantages of local and regional free autologous grafts.

ObjectiveTo investigate the feasibility and effect of a pedicled submental flap in postoperative defect repair of nasopharyngeal malignant tumors.MethodsEight cases (six women, two men; age, 29–63 years) of postoperative defects after resection of malignant nasopharyngeal tumors with a lesion stage of (r) T1–3N0–2M0 were retrospectively analyzed. Preoperative enhanced thin-slice computed tomography of the neck was performed to predict the submental flap reflux vein. The submental flap was prefabricated during the operation, and the nasopharyngeal mass was removed through the parapharyngeal space approach combined with nasal endoscopy/mandibular external rotation/maxillary overturning. The submental flap was elevated to the nasopharyngeal defect area through the parapharyngeal space for repair.ResultsIntraoperative examination confirmed that among the eight submental flaps, three had venous drainage into the internal jugular vein and five had venous drainage into the external jugular vein; these findings were consistent with the preoperative computed tomography findings. The size of the submental flap was 8–10 cm × 5–6 cm. The repair range reached the eustachian orifice on the healthy side and extended to the posterior wall of the maxillary sinus on the affected side. The flap extended to the posterior upper part of the nasal septum at the top, to the oropharynx at the bottom, and to the bony surface of the skull base at the deep side. Primary healing after surgery was achieved, and no flap necrosis occurred. After 3–77 months of follow-up, one patient with recurrent nasopharyngeal carcinoma after radiotherapy developed cervical lymph node recurrence again, one patient with adenoid cystic carcinoma had lung metastasis, and the remaining six patients had no recurrence.ConclusionsThe pedicled submental flap is used to repair postoperative defects in the nasopharyngeal region through the cervical parapharyngeal space. It is a simple and fast procedure with adequate tissue volumes. The flap can effectively protect important structures such as the internal carotid artery and reduce the risk of infection and bleeding from postoperative wound exposure.

Thermal conductivity and thermal dissipation are of great importance for modern electronics due to the increased transistor density and operation frequency of contemporary integrated circuits. Due to its exceptionally high thermal conductivity, graphene has drawn considerable interests worldwide for heat spreading and dissipation. However, maintaining high thermal conductivity in graphene laminates (the basic technological unit) is a significant technological challenge. Aiming at highly thermal conductive graphene films (GFs), this prospective review outlines the most recent progress in the production of GFs originated from graphene oxide due to its great convenience in film processing. Additionally, we also consider such issues as film assembly, defect repair and mechanical compression during the post-treatment. We also discuss the thermal conductivity in in-plane and through-plane direction and mechanical properties of GFs. Further, the current typical applications of GFs are presented in thermal management. Finally, perspectives are given for future work on GFs for thermal management.

Disputes due to defects in newly built houses are increasing worldwide. A house builder is responsible for repairing any defects in a newly built house. However, since house builders’ risk of closure and bankruptcy are increasing due to aggravated disputes and economic crises, builders may become insolvent and fail to perform defect repairs. In preparation for this, many countries have established defect repair deposit or guaranty insurance systems; however, the standards for these systems are not based an objective evidence since the current standards were arbitrarily established during industrialization. It has been pointed out that Korea’s housing defect repair deposit has been set excessively high and is being abused in disputes. Based on dispute cases in Korea, this study analyzed housing construction costs, deposits, and defect repair costs, resulting from lawsuits due to defects. The results confirmed that the defect repair deposit has been set too high compared to incurred defect repair costs. In addition, it was found that the guaranty insurance premium in lieu of the housing defect repair deposit was excessive compared to the damage caused by builder insolvency. In order to improve this, in this study, we proposed two alternative plans in which the housing defect repair deposit was set at a certain percentage of the construction cost based on the current Korean standard. In addition, based on the concept of different deposit levels using the scale of housing construction, such as in Australia and Canada, two additional alternative plans with different deposit ratios for each scale of housing construction were presented. The comparison results for housing defect repair deposits and guaranty insurance premiums based on the four presented alternative plans accompanied by actual cases showed that all the alternative plan deposits were higher than the actual defect repair costs. Even in the case of a guaranty insurance premium, the level was at least twice as high as the damage caused by builder insolvency. Therefore, all the alternative plans can fulfill their original role of protecting homeowners in the case of builder insolvency. At the same time, reducing the guaranty insurance premium to reflect the cost of housing construction is possible, and would benefit both house builders and home buyers. The results of this study are valuable as a reference for other countries considering establishing or revising a housing defect repair deposit system. Specifically, these findings, which analyzed the case of Korea’s socioeconomic changes as it transitioned from a developing country to a developed country, can provide important information for many developing countries operating housing defect repair deposit policies and systems.

Controllable repairing the vacancy-defects of BC3 monolayers is significantly important for their fundamental investigations and various applications. We performed first-principles calculations to present a promising strategy of controllable repairing of monovacancies in BC3 monolayer using CO and BF molecules. Two-step repairing process of C monovacancy was performed, the first of which is exposure to CO molecule that provides a C atom to fill the C vacancy, and the second step is removing the extra O atom on the BC3 monolayer via interacting with another CO molecule. In this case, a physisorbed CO2 molecule is formed and leaves the pure BC3 monolayer. However, a three-step repairing procedure for B monovacancy using BF molecule was explored, the first two steps of which are very akin to the case of C monovacancy, but the difference is the chemisorption of the BF2 molecule on the pure BC3 monolayer. We thus explored the third step to remove the BF2 molecule using heating method. At 600 K, BF2 molecule can desorb rapidly from the BC3 monolayer, while whose structural integrity remains. Our study reveals useful insight into the synthesis of perfect BC3 monolayers and presents a proposed strategy for repairing the single vacancies in BC3 monolayers.

In recent years, as for the frequent occurrence of failure accidents of high-grade steel pipelines caused by girth weld cracking, great attention has been drawn to the quality of girth weld and defect repair of high-grade steel pipelines. In terms of the types of girth weld defects of high-grade steel pipelines, the recommended treatment methods for girth weld defects in domestic and foreign repair standards for high-grade steel pipes were introduced, and the research results of the existing welding and non-welding repair technologies were systematically combed. As for welding repair technology, Type B sleeve is the preferred repair technology for repairing high-grade steel pipe girth weld defects. At present, the full-automatic welding technology for horizontal straight welds and circumferential fillet welds for open tee, guard plate and Type B sleeve has basically met the conditions for popularization and application, and is expected to greatly improve the welding efficiency and welding quality. Non-welding repair technology divides into three types: composite material, epoxy sleeve and steel lining composite material repair technology. A series of verification tests were conducted abroad to repair the defects (50% incomplete fusion) of X42 pipeline girth welds with composite materials and steel lining composite materials. Compared with composite materials, steel-lined composite materials perform better in axial tensile load test. In China, steel epoxy sleeve was used to reinforce the girth weld, which was inspected and evaluated to be unnecessary to repair but has defects, and the composite steel lining repair technology was designed based on the composite material and epoxy sleeve repair technology. Finally, the solution and key research directions were put forward to solve the problem of girth weld defect repair of high-grade pipelines, and supposed to provide technical reserves for the safe operation of China–Russia Eastern Gas Pipeline Project and similar high-grade pipelines.

Chronic tendon ruptures are common disorders in orthopedics. The conventional surgical methods used to treat them often require the support of implants. Due to the non-availability of suitable materials, 3D-printed polycaprolactone (PCL) scaffolds were designed from two different starting materials as suitable candidates for tendon-implant applications. For the characterization, mechanical testing was performed. To increase their biocompatibility, the PCL-scaffolds were plasma-treated and coated with fibronectin and collagen I. Cytocompatibility testing was performed using L929 mouse fibroblasts and human-bone-marrow-derived mesenchymal stem cells. The mechanical testing showed that the design adaptions enhanced the mechanical stability. Cell attachment was increased in the plasma-treated specimens compared to the control specimens, although not significantly, in the viability tests. Coating with fibronectin significantly increased the cellular viability compared to the untreated controls. Collagen I treatment showed an increasing trend. The desired cell alignment and spread between the pores of the construct was most prominent on the collagen-I-coated specimens. In conclusion, 3D-printed scaffolds are possible candidates for the development of tendon implants. Enhanced cytocompatibility was achieved through surface modifications. Although adaptions in mechanical strength still require alterations in order to be applied to human-tendon ruptures, we are optimistic that a suitable implant can be designed.

Pt, as a common cocatalyst, has been widely used in photocatalytic H2 evolution. However, the specific role of Pt in photocatalytic H2 evolution has not been thoroughly studied. In this paper, by employing three Pt sources with different charges (positive, negative and neutral), we systematically studied the charge effect of Pt sources on photocatalytic H2 evolution via TiO2 catalyst. According to the results of Raman, X-ray photoelectron spectroscopy (XPS), recycle experiments and photocurrent characterizations, it was found that TiO2 would produce electropositive defects during photocatalytic H2 evolution, inevitably leading to the decline of H2 production activity. Thanks to the electrostatic interaction, the electronegative Pt source not only promoted charge separation, but preferential deposited on electropositive defects, which acted as the defect repair agent, and thus resulted in the increased photocatalytic stability. This work may provide a new perspective for enhancing photocatalytic stability of hydrogen production.

Stem/progenitor cells can be used to repair defects in the airway wall, resulting from e.g., tumors, trauma, tissue reactions following long-time intubations, or diseases that are associated with epithelial damage. Several potential sources of cells for airway epithelium have been identified. These can be divided into two groups. The first group consists of endogenous progenitor cells present in the respiratory tract. This group can be subdivided according to location into (a) a ductal cell type in the submucosal glands of the proximal trachea, (b) basal cells in the intercartilaginous zones of the lower trachea and bronchi, (c) variant Clara cells (Clarav-cells) in the bronchioles and (d) at the junctions between the bronchioles and the alveolar ducts, and (e) alveolar type II cells. This classification of progenitor cell niches is, however, controversial. The second group consists of exogenous stem cells derived from other tissues in the body. This second group can be subdivided into: (a) embryonic stem (ES) cells, induced pluripotent stem (iPS) cells, or amniotic fluid stem cells, (b) side-population cells from bone marrow or epithelial stem cells present in bone marrow or circulation and (c) fat-derived mesenchymal cells. Airway epithelial cells can be co-cultured in a system that includes a basal lamina equivalent, extracellular factors from mesenchymal fibroblasts, and in an air-liquid interface system. Recently, spheroid-based culture systems have been developed. Several clinical applications have been suggested: cystic fibrosis, acute respiratory distress syndrome, chronic obstructive lung disease, pulmonary fibrosis, pulmonary edema, and pulmonary hypertension. Clinical applications so far are few, but include subglottic stenosis, tracheomalacia, bronchiomalacia, and emphysema.