RESUMO
The development of high-performance ultraelastic metals with superb strength, a large elastic strain limit and temperature-insensitive elastic modulus (Elinvar effect) are important for various industrial applications, from actuators and medical devices to high-precision instruments1,2. The elastic strain limit of bulk crystalline metals is usually less than 1 per cent, owing to dislocation easy gliding. Shape memory alloys3-including gum metals4,5 and strain glass alloys6,7-may attain an elastic strain limit up to several per cent, although this is the result of pseudo-elasticity and is accompanied by large energy dissipation3. Recently, chemically complex alloys, such as 'high-entropy' alloys8, have attracted tremendous research interest owing to their promising properties9-15. In this work we report on a chemically complex alloy with a large atomic size misfit usually unaffordable in conventional alloys. The alloy exhibits a high elastic strain limit (approximately 2 per cent) and a very low internal friction (less than 2 × 10-4) at room temperature. More interestingly, this alloy exhibits an extraordinary Elinvar effect, maintaining near-constant elastic modulus between room temperature and 627 degrees Celsius (900 kelvin), which is, to our knowledge, unmatched by the existing alloys hitherto reported.
RESUMO
Dragging of light by moving media was predicted by Fresnel1 and verified by Fizeau's celebrated experiments2 with flowing water. This momentous discovery is among the experimental cornerstones of Einstein's special relativity theory and is well understood3,4 in the context of relativistic kinematics. By contrast, experiments on dragging photons by an electron flow in solids are riddled with inconsistencies and have so far eluded agreement with the theory5-7. Here we report on the electron flow dragging surface plasmon polaritons8,9 (SPPs): hybrid quasiparticles of infrared photons and electrons in graphene. The drag is visualized directly through infrared nano-imaging of propagating plasmonic waves in the presence of a high-density current. The polaritons in graphene shorten their wavelength when propagating against the drifting carriers. Unlike the Fizeau effect for light, the SPP drag by electrical currents defies explanation by simple kinematics and is linked to the nonlinear electrodynamics of Dirac electrons in graphene. The observed plasmonic Fizeau drag enables breaking of time-reversal symmetry and reciprocity10 at infrared frequencies without resorting to magnetic fields11,12 or chiral optical pumping13,14. The Fizeau drag also provides a tool with which to study interactions and nonequilibrium effects in electron liquids.
RESUMO
Plasmon polaritons are hybrid excitations of light and mobile electrons that can confine the energy of long-wavelength radiation at the nanoscale. Plasmon polaritons may enable many enigmatic quantum effects, including lasing 1 , topological protection2,3 and dipole-forbidden absorption 4 . A necessary condition for realizing such phenomena is a long plasmonic lifetime, which is notoriously difficult to achieve for highly confined modes 5 . Plasmon polaritons in graphene-hybrids of Dirac quasiparticles and infrared photons-provide a platform for exploring light-matter interaction at the nanoscale6,7. However, plasmonic dissipation in graphene is substantial 8 and its fundamental limits remain undetermined. Here we use nanometre-scale infrared imaging to investigate propagating plasmon polaritons in high-mobility encapsulated graphene at cryogenic temperatures. In this regime, the propagation of plasmon polaritons is primarily restricted by the dielectric losses of the encapsulated layers, with a minor contribution from electron-phonon interactions. At liquid-nitrogen temperatures, the intrinsic plasmonic propagation length can exceed 10 micrometres, or 50 plasmonic wavelengths, thus setting a record for highly confined and tunable polariton modes. Our nanoscale imaging results reveal the physics of plasmonic dissipation and will be instrumental in mitigating such losses in heterostructure engineering applications.
RESUMO
Objective: To report the long-term survival of renal cell carcinoma (RCC) patients treated with radical nephrectomy in Sun Yat-sen University Cancer Center. Methods: We retrospectively analyzed the clinical, pathological and follow-up records of 1 367 non-metastatic RCC patients treated with radical nephrectomy from 1999 to 2020 in this center. The primary endpoint of this study was overall survival rate. Survival curves were estimated using the Kaplan-Meier method, and group differences were compared through Log-rank test. Univariate and multivariate Cox analysis were fit to determine the clinical and pathological features associated with overall survival rate. Results: A total of 1 367 patients treated with radical nephrectomy with complete follow-up data were included in the study. The median follow-up time was 52.6 months, and 1 100 patients survived and 267 died, with the median time to overall survival not yet reached. The 5-year and 10-year overall survival rates were 82.8% and 74.9%, respectively. The 5-year and 10-year overall survival rates of Leibovich low-risk patients were 93.3% and 88.2%, respectively; of Leibovich intermediate-risk patients were 82.2% and 72.3%, respectively; and of Leibovich high-risk patients were 50.5% and 30.2%, respectively. There were significant differences in the long-term survival among the three groups (P<0.001). The 10-year overall survival rates for patients with pT1, pT2, pT3 and pT4 RCC were 83.2%, 73.6%, 55.0% and 31.4%, respectively. There were significant differences among pT1, pT2, pT3 and pT4 patients(P<0.001). The 5-year and 10-year overall survival rates of patients with lymph node metastasis were 48.5% and 35.6%, respectively, and those of patients without lymph node metastasis were 85.1% and 77.5%, respectively. There was significant difference in the long-term survival between patients with lymph node metastasis and without lymph node metastasis. The 10-year overall survival rate was 96.2% for nuclear Grade 1, 81.6% for nuclear Grade 2, 60.5% for nuclear Grade 3, and 43.4% for nuclear Grade 4 patients. The difference was statistically significant. There was no significant difference in the long-term survival between patients with localized renal cancer (pT1-2N0M0) who underwent open surgery and minimally invasive surgery (10-year overall survival rate 80.5% vs 85.6%, P=0.160). Multivariate Cox analysis showed that age≥55 years (HR=2.11, 95% CI: 1.50-2.96, P<0.001), T stage(T3+ T4 vs T1a: HR=2.37, 95% CI: 1.26-4.46, P=0.008), local lymph node metastasis (HR=3.04, 95%CI: 1.81-5.09, P<0.001), nuclear grade (G3-G4 vs G1: HR=4.21, 95%CI: 1.51-11.75, P=0.006), tumor necrosis (HR=1.66, 95% CI: 1.17-2.37, P=0.005), sarcomatoid differentiation (HR=2.39, 95% CI: 1.31-4.35, P=0.005) and BMI≥24kg/m(2) (HR=0.56, 95%CI: 0.39-0.80, P=0.001) were independent factors affecting long-term survival after radical nephrectomy. Conclusions: The long-term survival of radical nephrectomy in patients with renal cell carcinoma is satisfactory. Advanced age, higher pathological stage and grade, tumor necrosis and sarcomatoid differentiation were the main adverse factors affecting the prognosis of patients. Higher body mass index was a protective factor for the prognosis of patients.
Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Pessoa de Meia-Idade , Carcinoma de Células Renais/secundário , Metástase Linfática , Estudos Retrospectivos , Estadiamento de Neoplasias , Neoplasias Renais/cirurgia , Neoplasias Renais/patologia , Prognóstico , Nefrectomia , Análise de Sobrevida , Necrose/patologia , Necrose/cirurgia , Taxa de SobrevidaRESUMO
Objective: To establish a nomogram prognostic model for predicting the 5-, 10-, and 15-year overall survival (OS) of non-metastatic renal cell carcinoma patients managed with radical nephrectomy (RN), compare the modelled results with the results of pure pathologic staging, the Karakiewicz nomogram and the Mayo Clinic Stage, Size, Grade, and Necrosis (SSIGN) score commonly used in foreign countries, and stratify the patients into different prognostic risk subgroups. Methods: A total of 1 246 non-metastatic renal cell carcinoma patients managed with RN in Sun Yat-sen University Cancer Center (SYSUCC) from 1999 to 2020 were retrospectively analyzed. Multivariate Cox regression analysis was used to screen the variables that influence the prognosis for nomogram establishment, and the bootstrap random sampling was used for internal validation. The time-receiver operating characteristic curve (ROC), the calibration curve and the clinical decision curve analysis (DCA) were applied to evaluate the nomogram. The prediction efficacy of the nomogram and that of the pure pathologic staging, the Karakiewicz nomogram and the SSIGN score was compared through the area under the curve (AUC). Finally, patients were stratified into different risk subgroups according to our nomogram scores. Results: A total of 1 246 patients managed with RN were enrolled in this study. Multivariate Cox regression analysis showed that age, smoking history, pathological nuclear grade, sarcomatoid differentiation, tumor necrosis and pathological T and N stages were independent prognostic factors for RN patients (all P<0.05). A nomogram model named SYSUCC based on these factors was built to predict the 5-, 10-, and 15-year survival rate of the participating patients. In the bootstrap random sampling with 1 000 iterations, all these factors occurred for more than 800 times as independent predictors. The Harrell's concordance index (C-index) of SYSUCC was higher compared with pure pathological staging [0.770 (95% CI: 0.716-0.823) vs 0.674 (95% CI: 0.621-0.728)]. The calibration curve showed that the survival rate as predicted by the SYSUCC model simulated the actual rate, while the clinical DCA showed that the SYSUCC nomogram has a benefit in certain probability ranges. In the ROC analysis that included 857 patients with detailed pathological nuclear stages, the nomogram had a larger AUC (5-/10-year AUC: 0.823/0.804) and better discriminating ability than pure pathological staging (5-/10-year AUC: 0.701/0.658), Karakiewicz nomogram (5-/10-year AUC: 0.772/0.734) and SSIGN score (5-/10-year AUC: 0.792/0.750) in predicting the 5-/10-year OS of RN patients (all P<0.05). In addition, the AUC of the SYSUCC nomogram for predicting the 15-year OS (0.820) was larger than that of the SSIGN score (0.709), and there was no statistical difference (P<0.05) between the SYSUCC nomogram, pure pathological staging (0.773) and the Karakiewicz nomogram (0.826). The calibration curve was close to the standard curve, which indicated that the model has good predictive performance. Finally, patients were stratified into low-, intermediate-, and high-risk subgroups (738, 379 and 129, respectively) according to the SYSUCC nomogram scores, among whom patients in intermediate- and high-risk subgroups had a worse OS than patients in the low-risk subgroup (intermediate-risk group vs. low-risk group: HR=4.33, 95% CI: 3.22-5.81, P<0.001; high-risk group vs low-risk group: HR=11.95, 95% CI: 8.29-17.24, P<0.001), and the high-risk subgroup had a worse OS than the intermediate-risk group (HR=2.63, 95% CI: 1.88-3.68, P<0.001). Conclusions: Age, smoking history, pathological nuclear grade, sarcomatoid differentiation, tumor necrosis and pathological stage were independent prognostic factors for non-metastasis renal cell carcinoma patients after RN. The SYSUCC nomogram based on these independent prognostic factors can better predict the 5-, 10-, and 15-year OS than pure pathological staging, the Karakiewicz nomogram and the SSIGN score of patients after RN. In addition, the SYSUCC nomogram has good discrimination, agreement, risk stratification and clinical application potential.
Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Nomogramas , Estudos Retrospectivos , Carcinoma de Células Renais/cirurgia , Carcinoma de Células Renais/patologia , Prognóstico , Fatores de Risco , Nefrectomia , Neoplasias Renais/cirurgia , Neoplasias Renais/patologia , NecroseRESUMO
Objectives: To analyze the factors relative to the short-term preservation of ipsilateral renal function after partial nephrectomy. Methods: The clinical data of 83 patients who were treated with partial nephrectomy from December 2014 to December 2019 in the Department of Urology, Sun Yat-sen University Cancer Center were retrospectively analyzed. There were 54 males and 29 females, aging (M (IQR)) 49 (17) years (range: 27 to 74 years). The ischemia time in operation was 25 (18) minutes (range: 10 to 67 minutes). Emission computed tomography scan and CT scan were performed before (within 1 month) and after (3 to 12 months) surgery. The volume of the ipsilateral and contralateral kidney was measured on the basis of preoperative and postoperative CT scans. The glomerular filtration rate (GFR) specifically in each kidney was estimated by emission computed tomography. Recovery from ischemia is determined by the formula: GFR preservation/volume saved×100%. Linear regression was used to explore the factors ralative to the short-term preservation of ipsilateral renal function after partial nephrectomy. Results: The GFR preservation of the ipsilateral kidney was 80.9 (25.2) % (range: 31.0% to 109.4%). The volume loss of the kidney resulted in a decrease of 12.0% (5.8 ml/(min×1.96 m2)) of GFR, while the ischemic injury resulted in a decrease of 6.5% (2.5 ml/(min×1.96 m2)) of GFR. The volume saved from the ipsilateral kidney was 87.1 (12.9) % (range: 27.0% to 131.7%). Recovery from ischemia was 93.5 (17.5) % (range:44.3% to 178.3%). In multivariate analysis, GFR preservation of the ipsilateral kidney was significantly correlated with the volume saved of the ipsilateral kidney (ß=0.383, 95%CI: 0.144 to 0.622, P=0.002). It was not related to the ischemia time (ß=0.046, 95%CI:-0.383 to 0.475, P=0.831). Conclusion: In the condition of limited ischemic time, in the short term ipsilateral renal function after partial nephrectomy is mainly determined by the loss of kidney volume, while ischemic injury only plays a minor role.
Assuntos
Neoplasias Renais , Masculino , Feminino , Humanos , Neoplasias Renais/cirurgia , Estudos Retrospectivos , Isquemia Quente/efeitos adversos , Nefrectomia/efeitos adversos , Nefrectomia/métodos , Rim , Isquemia/cirurgia , Taxa de Filtração GlomerularRESUMO
Objectives: To analyze the long-term survival of patients with localized renal cell carcinoma after partical nephrectomy. Methods: The clinicopathological records and survival follow-up data of 2 046 patients with localized renal cell carcinoma, who were treated with partial nephrectomy from August 2001 to February 2021 in the Department of Urology, Sun Yat-sen University Cancer Center, were retrospectively analyzed. There were 1 402 males and 644 females, aged (M(IQR)) 51 (19) years (range: 6 to 86 years). The primary end point of this study was cancer-specific survival. Survival curves were estimated using the Kaplan-Meier method, and the difference test was performed by Log-rank test. Univariate and multivariate Cox analysis were fitted to determine factors associated with cancer-specific survival. Results: The follow-up time was 49.2 (48.0) months (range: 1 to 229 months), with 1 974 patients surviving and 72 dying. The median cancer-specific survival time has not yet been reached. The 5- and 10-year cancer specific survival rates were 97.0% and 91.2%, respectively. The 10-year cancer-specific survival rates for stage pT1a (n=1 447), pT1b (n=523) and pT2 (n=58) were 95.3%, 81.8%, and 81.7%, respectively. The 10-year cancer-specific survival rates of patients with nuclear grade 1 (n=226), 2 (n=1 244) and 3 to 4 (n=278) were 96.6%, 89.4%, and 85.5%, respectively. There were no significant differences in 5-year cancer-specific survival rates among patients underwent open, laparoscopic, or robotic surgery (96.7% vs. 97.1% vs. 97.5%, P=0.600). Multivariate analysis showed that age≥50 years (HR=3.93, 95%CI: 1.82 to 8.47, P<0.01), T stage (T1b vs. T1a: HR=3.31, 95%CI: 1.83 to 5.99, P<0.01; T2+T3 vs. T1a: HR=2.88, 95%CI: 1.00 to 8.28, P=0.049) and nuclear grade (G3 to 4 vs. G1: HR=2.81, 95%CI: 1.01 to 7.82, P=0.048) were independent prognostic factors of localized renal cell carcinoma after partial nephrectomy. Conclusions: The long-term cancer-specific survival rates of patients with localized renal cancer after partial nephrectomy are satisfactory. The type of operation (open, laparoscopic, or robotic) has no significant effect on survival. However, patients with older age, higher nuclear grade, and higher T stage have a lower cancer-specific survival rate. Grasping surgical indications, attaching importance to preoperative evaluation, perioperative management, and postoperative follow-up, could benefit achieving satisfactory long-term survival.
RESUMO
Butyrate-producing bacteria generate butyrate, which has antidepressant effects. Xiaoyaosan (XYS), a traditional Chinese medicine (TCM) used to treat depression, may improve depression-like behaviour by modulating the gut microbiota. However, the functional groups and mechanisms of action in the XYS treatment of depression remain unknown. This study aimed to analyse with clone sequencing the changes in intestinal butyrate-producing bacteria in XYS-treated chronic unpredictable mild stress (CUMS) rats. We successfully established the XYS-treated CUMS rat model of depression. Rat faecal samples were collected before, during, and after the experiment, and butyryl-CoA:acetate CoA-transferase gene primers were selected for PCR amplification to determine the diversity of butyrate-producing bacteria. The results showed that XYS increased intestinal butyrate-producing bacterial diversity in CUMS rats regarding phylum and genus numbers; the number of phyla increased to two, distributed in Firmicutes and Bacteroides, and four genera were distributed in Eubacterium sp., Roseburia sp., Clostridium sp. and Bacteroides sp. Only one phylum and two genera were present in the model group without XYS treatment. Our findings indicate that XYS can improve depression-like behaviour by regulating intestinal butyrate-producing bacteria diversity, particularly Roseburia sp. and Eubacterium sp., thus providing new insights into the targeted regulation of the intestinal flora to treat depression.
Assuntos
Coenzima A-Transferases , Depressão , Acetatos , Animais , Antidepressivos/farmacologia , Bactérias , Comportamento Animal , Butiratos/farmacologia , Coenzima A-Transferases/farmacologia , Depressão/tratamento farmacológico , Depressão/genética , Depressão/microbiologia , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas , RatosRESUMO
OBJECTIVE: To investigate the efficacy and safety of laparoscopic pyeloplasty combined with ultrasonic lithotripsy via nephroscope in the treatment of ureteropelvic junction obstruction (UPJO) with renal calculi. METHODS: From June 2016 to January 2022, eight patients including five males and three females underwent laparoscopic pyeloplasty combined with ultrasonic lithotripsy via 19.5F(1F≈0.33 mm) nephroscope in Peking University People' s Hospital. The age ranged from 23-51 years (mean: 40.5 years) and the body mass index (BMI) ranged from 18.8-32.4 kg/m2 (mean 27.0 kg/m2). The lesion located on the left side in all of the eight patients. Two patients had solitary kidney and one patient had horseshoe kidney. Solitary stone was seen in one patient and the other seven patients suffered multiple stones, with two patients had staghorn stones. The largest diameter of stones ranged from 0.6-2.5 cm (mean: 1.5 cm). CT or ultrasound showed that moderate nephrosis was seen in five patients and severe nephrosis was seen in three patients. During surgery, after exposure of renal pelvis and proximal ureter, a small incision of 1.5 cm was performed in the anterior wall of the renal pelvis, and a 19.5F nephroscope was introduced into renal pelvis through laparoscopic trocar and renal pelvis incision. Stones were fragmented and sucked out by 3.3 mm ultrasonic probe placed through nephroscope. After stones were removed, modified laparoscopic pyeloplasty was performed. RESULTS: Surgery was successfully completed in all of the eight patients without conversion to open surgery. The operation time ranged from 160-254 min (mean 213 min) and the time of nephroscopic management time was 25-40 min (mean: 33 min). The hemoglobin was decreased by 3-21 g/L (mean: 10.3 g/L). The stone-free rate was 75% (6/8 cases), stones were incompletely removed in two patients due to abnormal intrarenal structure. The modified Clavien classification system (MCCS) grade â ¢A complication occurred in one patient postoperatively, which was nephrosis due to intrarenal bleeding, and nephrostomy was performed. With the mean follow-up of 30 months (ranged from 2-68 months), there was no evidence of obstruction in all the patients, and one patient underwent percutaneous nephrolithotomy to treat residual calculi. CONCLUSION: Laparoscopic pyeloplasty combined with ultrasonic lithotripsy via 19.5F nephroscope is feasible and safe, and could be a complementary method to treat UPJO and renal calculi.
Assuntos
Cálculos Renais , Laparoscopia , Litotripsia , Nefrose , Ureter , Obstrução Ureteral , Adulto , Feminino , Humanos , Cálculos Renais/cirurgia , Pelve Renal , Laparoscopia/métodos , Masculino , Pessoa de Meia-Idade , Nefrose/complicações , Nefrose/cirurgia , Obstrução Ureteral/cirurgia , Adulto JovemRESUMO
Time-series and case-crossover are two main study designs in environmental epidemiology. However, due to the differences in design principles and model construction between the two analyses, the results of the two analyses may not be consistent. Herein, we examined the short-term effect of cold spells on cardiovascular mortality in Nanjing using both time series and case-crossover analyses, aiming to provide a basis for the selection of appropriate research design in environmental epidemiology.
Assuntos
Estudos Cross-Over , Humanos , Fatores de TempoRESUMO
OBJECTIVE: To evaluate the utility of expanded non-invasive prenatal screening (NIPS), compared with chromosomal microarray analysis (CMA), for the detection of chromosomal abnormalities in high-risk pregnancies. METHODS: This was a multicenter retrospective study of singleton pregnancies at high risk for chromosomal abnormality. Patients who underwent expanded NIPS and CMA sequentially during pregnancy from 2015 to 2019 were included in the analysis. Pregnancies with a positive result for sex chromosome aneuploidy were excluded as the full details could not be retrieved. The utility of expanded NIPS and CMA for detection of chromosomal abnormalities in this cohort was compared by assessing the concordance between the results. RESULTS: Of the 774 included high-risk pregnancies, 550 (71.1%) had a positive NIPS result, while a positive CMA result was detected in 308 (39.8%) cases. The rate of full or partial concordance between NIPS and CMA was 82.2%, 59.6% and 25.0% for trisomies 21, 18 and 13, respectively. For rare aneuploidies and segmental imbalances, NIPS and CMA results were fully or partially concordant in 7.5% and 33.3% of cases, respectively. Copy-number variants < 5 Mb were detected more often by CMA, with an incidence of 7.9% (61/774) compared with 3.1% (24/774) by NIPS. A genetic aberration was detected by CMA in 1 in 17 (5.8%) high-risk pregnancies that had a negative or non-reportable NIPS result. CONCLUSION: CMA allows for comprehensive detection of genome-wide chromosomal abnormalities in high-risk pregnancies. CMA should be offered instead of expanded NIPS for high-risk pregnancies. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.
Assuntos
Aberrações Cromossômicas/embriologia , Transtornos Cromossômicos/diagnóstico , Análise em Microsséries/estatística & dados numéricos , Teste Pré-Natal não Invasivo/estatística & dados numéricos , Gravidez de Alto Risco/genética , Adulto , Transtornos Cromossômicos/embriologia , Feminino , Humanos , Análise em Microsséries/métodos , Teste Pré-Natal não Invasivo/métodos , Gravidez , Reprodutibilidade dos Testes , Estudos Retrospectivos , Adulto JovemRESUMO
An outbreak of new severe acute respiratory syndrome coronavirus disease, coronavirus disease 2019 (COVID-19), has emerged during December 2019. The ongoing outbreak in Wuhan City spread rapidly throughout China, where the fatality rate ranged from 2.1 to 4.9%. Due to its high transmissibility, the World Health Organization (WHO) declared a public health emergency of international concern on 30 January 2020. The current outbreak has the potential to become the first pandemic of the new millennium. Most patients who were first diagnosed with COVID-19 worked at or lived in the vicinity of the local Huanan Seafood Wholesale Market, where live animals were also on sale. The concerted efforts of Chinese scientists led to the independent isolation from patients and identification of a novel coronavirus, SARS coronavirus 2 (SARS-CoV-2), on 6 January 2020; this has been an important step in the development of treatment. The purpose of this article is to overview the history, epidemiology, clinical characteristics, diagnosis, and treatment of COVID 2019 reported in recently published studies. Based on the results of virus genome sequencing and a model of the interaction between host cells and the virus, we propose several possible targets for antiviral drugs, which may provide new ideas for epidemic control and vaccine development. Keywords: 2019 novel coronavirus; pneumonia; SARS-CoV-2; Coronaviridae; COVID-19.
Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus , Pandemias , Pneumonia Viral , Animais , COVID-19 , China , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/terapia , Humanos , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Pneumonia Viral/terapia , SARS-CoV-2RESUMO
Intervertebral disc (IVD) degeneration is frequently associated with Low back pain (LBP), which can severely reduce the quality of human life and cause enormous economic loss. However, there is a lack of long-lasting and effective therapies for IVD degeneration at present. Recently, stem cell based tissue engineering techniques have provided novel and promising treatment for the repair of degenerative IVDs. Numerous studies showed that stem/progenitor cells exist naturally in IVDs and could migrate from their niche to the IVD to maintain the quantity of nucleus pulposus (NP) cells. Unfortunately, these endogenous repair processes cannot prevent IVD degeneration as effectively as expected. Therefore, theoretical basis for regeneration of the NP in situ can be obtained from studying the mechanisms of endogenous repair failure during IVD degeneration. Although there have been few researches to study the mechanism of cell death and migration of stem/progenitor cells in IVD so far, studies demonstrated that the major inducing factors (compression and hypoxia) of IVD degeneration could decrease the number of NP cells by regulating apoptosis, autophagy, and necroptosis, and the particular chemokines and their receptors played a vital role in the migration of mesenchymal stem cells (MSCs). These studies provide a clue for revealing the mechanisms of endogenous repair failure during IVD degeneration. This article reviewed the current research situation and progress of the mechanisms through which IVD stem/progenitor cells failed to repair IVD tissues during IVD degeneration. Such studies provide an innovative research direction for endogenous repair and a new potential treatment strategy for IVD degeneration.
Assuntos
Degeneração do Disco Intervertebral/terapia , Transplante de Células-Tronco/métodos , Apoptose/fisiologia , Autofagia/fisiologia , Movimento Celular/fisiologia , Humanos , Degeneração do Disco Intervertebral/patologia , Células-Tronco Mesenquimais/fisiologia , Necroptose/fisiologia , Núcleo Pulposo/patologia , Nicho de Células-Tronco/fisiologia , Células-Tronco/patologia , Células-Tronco/fisiologia , Engenharia Tecidual/métodos , Falha de TratamentoRESUMO
OBJECTIVE: To investigate the management of crossing vessels compression in laparoscopic pyeloplasty. METHODS: From January 2016 to June 2018, a total of 21 patients who were admitted to Peking University People's Hospital with ureteropelvic junction obstruction (UPJO) associated with crossing vascular compression were reviewed. There were 15 males and 6 females who formed this group, with a mean age of (33.9±15.0) years. There were 4 cases of mild hydronephrosis, 12 cases of moderate hydronephrosis and 5 cases of severe hydronephrosis before operation. All the patients underwent laparoscopic pyeloplasty in our hospital, including 13 on the left and 8 on the right. Laparoscopic pyeloplasty (Anderson-Hynes) were performed in all the patients. Hem-o-lok suspension (14 cases in the suspension group) or translocation of the crossing vessels (7 cases in the translocation group) were used for the intraoperative management of the crossing vessels. Double J tubes were removed 8 weeks postoperatively. The patient demographic data were collected (including operation time, treatment time of crossing vessels, intraoperative blood loss, time of drainage tube removal after operation, and average length of hospital stay), postoperative outcomes were evaluated and the patients were followed up regularly. RESULTS: In all the patients, the crossing vessels were successfully reserved, and none of them were ligated intra-operatively. Mean operative times were (202.2±57.0) min. The duration of intraoperative treatment of crossing vessels was (10.5±3.2) min, (6.1±2.0) min in the suspension group, and (13.7±5.2) min in the translocation group, respectively. Intraoperative blood loss was (47.8±25.6) mL, postoperative drainage time was (4.8±2.6) d, and length of hospital stay was (11.5±3.3) d. Postoperative slight urinary leakage occurred in 1 case. Preoperative pyelectasis of the affected side of all the patients was (3.4±1.7) cm, compared with postoperative pyelectasis of (1.9±1.3) cm. The difference was statistically significant (P<0.05). Postoperative follow-up of all the patients was carried out until December 2018. There was no significant difference in kidney size in all the patients before or after the operations, and hydronephrosis was alleviated compared with that before surgery. CONCLUSION: For UPJO patients with crossing vascular compression, according to the location of the crossing vessels, Hem-o-lok suspension or vessel transposition can be adopted to relieve the crossing vascular compression and improve the success rate of the surgery.
Assuntos
Hidronefrose , Laparoscopia , Obstrução Ureteral , Adolescente , Adulto , Feminino , Humanos , Pelve Renal , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Procedimentos Cirúrgicos Urológicos , Adulto JovemRESUMO
OBJECTIVE: To evaluate the safety and efficacy of endoscopic treatment for ureterovesical junction (UVJ) stenosis in patients with kidney transplantation. METHODS: A retrospective study was conducted among the patients with kidney transplantation diagnosed as UVJ stenosis from 2012 March to 2018 July in Urology and Lithotripsy Center, Peking University People's Hospital. Only the patients who received endoscopic treatment were included, with staged or same-session nephrostomy followed by a retrograde ureteroscopy to evaluate the ureteral stenosis. Incisions with laser, mono- or bipolar energy, or balloon dilation were used to manage the stenosis depending on different situations. Demographic characteristics and clinical data were gathered and analyzed, including age, gender, preoperative serum creatinine, hemoglobin, operation time, success rate, postoperative serum creatinine, hemoglobin, postoperative complications rate, and long-term stenosis recurrence rate. RESULTS: In this study, 13 patients were included (9 males and 4 females). All the UVJ stenoses were diagnosed with preoperative ultrasound, CT scan, MRI, or urethrography. The mean age was 45 years (range 34-57 years). The mean preoperative serum creatinine was 243 µmol/L. Four patients developed UVJ stenosis 1 month after kidney transplantation, while the rest developed long-term stenosis. Fifteen operations were performed in all, of which 14 cases were successful while one failed. The first 8 cases received first-stage nephrostomy and second-stage endoscopic management of the stenosis, while the last 7 cases received the same session surgery. The mean operation time was 95.4 min vs. 68.9 min, and the immediate success rate was 87.5% vs. 100.0% in the first 8 cases and last 7 cases, respectively. The mean decrease of postoperative hemoglobin was 0.6 g/L and mean postoperative serum creatinine was 105 µmol/L. No postoperative fever, severe hematuria, and urine leak were observed. The mean postoperative hospital stay was 2.8 days. Three patients were able to remove ureteral stents and no recurrence was found with a follow-up time of 9, 17, and 82 months. The long-term stenosis recurrence rate was 76.9% (10/13). CONCLUSION: Endoscopic approach for the treatment of UVJ stenosis in patients with kidney transplantation was safe and efficient in our study cohort. However, long term stenosis recurrence rate was high and needed to be paid attention to.
Assuntos
Transplante de Rim , Obstrução Ureteral , Adulto , Feminino , Humanos , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Obstrução Ureteral/etiologia , UreteroscopiaRESUMO
An efficient, convenient short synthetic procedure for the synthesis of the intricate 5A5B6C-ring fusion topologies of tricyclic spiranoid ß-hydroxybutyrolactones through lactonization of the key intermediate trans-α-hydroxyindenones with malonates is described. All the compounds synthesized exhibited environmentally benign characteristics, moderate fungicidal, nematocidal, and anti-TMV activities.
RESUMO
OBJECTIVE: To evaluate whether targeted sequencing and relative mutation dosage can be used to diagnose correctly inheritance of maternal ß-thalassaemia mutations in cell-free DNA. DESIGN: Feasibility study using samples collected in a prenatal clinic. SETTING: South East Asia. POPULATION: Couples where both partners were known to be carriers of one of four common ß-thalassaemia mutations or an HbE mutation, and therefore at risk of carrying a fetus affected with ß-thalassaemia. METHODS: 49 samples previously identified as having inherited a paternal ß-thalassaemia mutation were amplified using nested polymerase chain reaction (PCR), and then sequencing. Relative mutation dosage was used to classify the fetus as having inherited the wild-type or mutant maternal allele. MAIN OUTCOME MEASURES: Classification of the fetus as 'unaffected' (if the maternal wild-type allele was inherited) or 'affected' with ß-thalassaemia (if the maternal mutant allele was inherited). RESULTS: A classification for inheritance of maternal allele was obtained in 48/49 samples (98.0%). A concordant call was made in 44/48 cases (91.7%): one false-positive and three false-negatives were obtained. Thus, we had an overall sensitivity of 87.5% [95% confidence interval (CI) 67.6-97.3%] and a specificity of 95.8% (95% CI 78.9-99.9%) for inheritance of maternal genotype. CONCLUSIONS: RMD for detection of inheritance of maternal ß-thalassaemia mutations has potential for clinical use. Our sequential approach could be applied to other single-gene disorders. TWEETABLE ABSTRACT: NIPT for ß-thalassaemia achieved using nested-PCR followed by relative mutation dosage.
Assuntos
Doenças Fetais , Mutação , Diagnóstico Pré-Natal/métodos , Análise de Sequência de DNA/métodos , Talassemia beta , Adulto , Sudeste Asiático , Ácidos Nucleicos Livres/análise , Análise Mutacional de DNA , Estudos de Viabilidade , Feminino , Doenças Fetais/diagnóstico , Doenças Fetais/genética , Humanos , Padrões de Herança , Masculino , Gravidez , Talassemia beta/diagnóstico , Talassemia beta/genéticaRESUMO
BACKGROUND: Acne is a common skin condition in developed countries with western diets. The effect of milk on acne has been highly controversial. To examine the association between milk consumption and acne risk, we conducted a meta-analysis of available data. MATERIALS AND METHODS: We carried out comprehensive databases search of PubMed, Embase, Medline and Cochrane Library and identified four cohort studies and nine case-control or cross-sectional studies, including a total of 71 819 participants. We evaluated the pooled odds ratio (OR) with its 95% confidence interval (CI) using a random effects model. Subgroup analyses on acne severity, milk forms and milk intake levels were performed. RESULTS: Compared with non-consumers, the pooled OR was 1.16 (95% CI 1.09-1.24) for overall milk consumers in all included studies, and 1.17 (95% CI 1.10-1.24) in cohort studies and 1.16 (95% CI 1.09-1.24) in case-control or cross-sectional studies. Subgroup analysis on milk forms determined a stronger association in skim milk consumers (OR = 1.24, 95% CI 1.13-1.37) than in low-fat consumers (OR = 1.14, 95% CI 1.08-1.22) and full-fat consumers (OR = 1.13, 95% CI 1.05-1.21). The pooled OR was greater for high intake level of milk (OR = 1.12, 95% CI 1.01-1.24) than medium intake level of milk (OR = 1.08, 95% CI 1.00-1.17). A subset study of moderate-to-severe acne also found a positive association with milk consumption (OR 1.18, 95% CI 1.01-1.37), while no statistically significant association was found between mild acne risk and milk consumption (OR 1.14, 95% CI 0.86-1.51). CONCLUSION: This meta-analysis provides evidence of a positive association between milk consumption and acne risk.
Assuntos
Acne Vulgar/epidemiologia , Ingestão de Líquidos , Leite , Animais , Estudos de Casos e Controles , Estudos Transversais , Humanos , Estudos Observacionais como Assunto , Fatores de Risco , Índice de Gravidade de DoençaRESUMO
Objective: To investigate the relationship between gastroesophageal reflux disease (GERD) and obstructive sleep apnea syndrome(OSAS). Methods: Patients diagnosed as GERD and healthy controls without GERD related symptoms or endoscopic esophagitis were enrolled from October 2017 and December 2017. All subjects completed Berlin Questionaire to assess the risk of OSAS. Univariate and multivariate logistic regression models were applied to identify risk factors of OSAS. Results: A total of 177 subjects (97 GERD, 80 controls) were finally selected. Significantly more patients in GERD group had high risk OSAS than those in controls [36.1%(35/97) vs. 17.5%(14/80), P=0.005]. In GERD group, patients with erosive reflux diseases (ERD) had especially higher proportion of high risk OSAS compared with the non-ERD group and the healthy controls [53.3% (24/45) vs. 20.8% (10/48) and 17.5% (14/80), P=0.001]. On univariate analysis, male, aging and reflux esophagitis were identified as risk factors of OSAS (all P<0.01). On multivariate analysis, male (OR=12.156, 95%CI 1.382-106.905, P=0.024), aging (OR=1.132, 95%CI 1.051-1.220, P=0.001), acid regurgitation with reflux esophagitis (OR=5.157, 95%CI 1.327-20.034, P=0.018) were significant risk factors. Conclusions: More GERD patients are combined with high risk OSAS than controls, especially subjects with reflux esophagitis. Male and aging GERD patients with acid regurgitation and reflux esophagitis need further evaluation on OSAS screening.