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Capturing CO2 using clamshell/eggshell-derived CaO adsorbent can not only reduce carbon emissions but also alleviate the impact of trash on the environment. However, organic acid was usually used, high-temperature calcination was often performed, and CO2 was inevitably released during preparing CaO adsorbents from shell wastes. In this work, CaO-based CO2 adsorbent was greenly prepared by calcium-induced hydrogenation of clamshell and eggshell wastes in one pot at room/moderate temperature. CO2 adsorption experiments were performed in a thermogravimetric analyzer (TGA). The adsorption performance of the adsorbents obtained from the mechanochemical reaction (BM-C/E-CaO) was superior to that of the adsorbents obtained from the thermochemical reaction (Cal-C/E-CaO). The CO2 adsorption capacity of BM-C-CaO at 650 °C is up to 36.82 wt%, but the adsorption decay rate of the sample after 20 carbonation/calcination cycles is only 30.17%. This study offers an alternative energy-saving method for greenly preparing CaO-based adsorbent from shell wastes.
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Dióxido de Carbono , Tecnología Química Verde , Eliminación de Residuos , Tecnología Química Verde/métodos , Dióxido de Carbono/análisis , Dióxido de Carbono/química , Hidrogenación , Temperatura , Exoesqueleto/química , Cáscara de Huevo/química , Eliminación de Residuos/métodos , AdsorciónRESUMEN
The aim of this study was to investigate the anti-inflammatory effects and mechanism of isovitexin on ulcerative colitis mice and RAW264.7 cells. The results showed that isovitexin had strong antioxidant and anti-inflammatory effects, and could restore intestinal barrier integrity (p < 0.01). In addition, isovitexin inhibited the expression of MyD88, TLR4 and NF-κB p65 proteins. At the same time, isovitexin can inhibit the activation of MAPK/NF-κB signaling pathway in RAW264.7 cells. In conclusion, isovitexin has a protective effect on UC mice, and its improvement mechanism of UC might be related to MAPK/NF-κB signaling pathway.
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One of the manifestations of renal aging is podocyte dysfunction and loss, which are associated with proteinuria and glomerulosclerosis. Studies show a male bias in glomerular dysfunction and chronic kidney diseases, and the underlying mechanisms remain obscure. Recent studies demonstrate the role of an age-associated increase in arginase-II (Arg-II) in proximal tubules of both male and female mice. However, it is unclear whether Arg-II is also involved in aging glomeruli. The current study investigates the role of the sex-specific elevation of Arg-II in podocytes in age-associated increased albuminuria. Young (3-4 months) and old (20-22 months) male and female mice of wt and arginase-II knockout (arg-ii-/-) were used. Albuminuria was employed as a readout of glomerular function. Cellular localization and expression of Arg-II in glomeruli were analyzed using an immunofluorescence confocal microscope. A more pronounced age-associated increase in albuminuria was found in male than in female mice. An age-associated induction of Arg-II in glomeruli and podocytes (as demonstrated by co-localization of Arg-II with the podocyte marker synaptopodin) was also observed in males but not in females. Ablation of the arg-ii gene in mice significantly reduces age-associated albuminuria in males. Also, age-associated decreases in podocyte density and glomerulus hypertrophy are significantly prevented in male arg-ii-/- but not in female mice. However, age-associated glomerulosclerosis is not affected by arg-ii ablation in both sexes. These results demonstrate a role of Arg-II in sex-specific podocyte injury in aging. They may explain the sex-specific differences in the development of renal disease in humans during aging.
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Podocitos , Animales , Femenino , Masculino , Ratones , Albuminuria/metabolismo , Arginasa/genética , Arginasa/metabolismo , Glomérulos Renales/metabolismo , Podocitos/metabolismo , Proteinuria/metabolismoRESUMEN
Hypoxia is an important risk for renal disease. The mitochondrial enzyme arginase-II (Arg-II) is expressed and/or induced by hypoxia in proximal tubular epithelial cells (PTECs) and in podocytes, leading to cellular damage. Because PTECs are vulnerable to hypoxia and located in proximity to podocytes, we examined the role of Arg-II in the crosstalk of PTECs under hypoxic conditions with podocytes. A human PTEC cell line (HK2) and a human podocyte cell line (AB8/13) were cultured. Arg-ii gene was ablated by CRISPR/Case9 in both cell types. HK2 cells were exposed to normoxia (21% O2) or hypoxia (1% O2) for 48 h. Conditioned medium (CM) was collected and transferred to the podocytes. Podocyte injuries were then analyzed. Hypoxic (not normoxic) HK2-CM caused cytoskeletal derangement, cell apoptosis, and increased Arg-II levels in differentiated podocytes. These effects were absent when arg-ii in HK2 was ablated. The detrimental effects of the hypoxic HK2-CM were prevented by TGF-ß1 type-I receptor blocker SB431542. Indeed, TGF-ß1 levels in hypoxic HK2-CM (but not arg-ii-/--HK2-CM) were increased. Furthermore, the detrimental effects of TGF-ß1 on podocytes were prevented in arg-ii-/--podocytes. This study demonstrates crosstalk between PTECs and podocytes through the Arg-II-TGF-ß1 cascade, which may contribute to hypoxia-induced podocyte damage.
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Túbulos Renales Proximales , Comunicación Paracrina , Podocitos , Humanos , Apoptosis , Arginasa/metabolismo , Células Epiteliales/metabolismo , Túbulos Renales Proximales/metabolismo , Comunicación Paracrina/genética , Podocitos/metabolismo , Podocitos/patología , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
Activated carbon is commonly used to remove dioxins from flue gas via adsorption. Improving the targeted adsorption capacity of activated carbon for dioxins can reduce the consumption of adsorbents and help achieve emission standards for target pollutants. Here, commercial coal-based activated carbon was used as a raw material and modified by urea impregnation along with treatment at high temperature under a nitrogen atmosphere. It was found that modification with urea effectively improved the pore structure of activated carbon while incorporating a certain amount of nitrogen. The best modification effect was achieved at a modification temperature of 600 °C, an impregnation ratio of urea to activated carbon of 1:1, and with high-temperature treatment for 2 h. The mesopore volume of the modified activated carbon (AC600) reached 0.38 cm3/g, accounting for 57.58% of the total pore volume. With an impregnation ratio of urea to activated carbon of 1:1, high-temperature treatment for 2 h, and a modification temperature of 800 °C, a certain amount of nitrogen was introduced into the carbon rings to form a modified activated carbon (AC800) rich in pyridine and pyrrole groups (atomic percentage = 4.84%). The activated carbon modified by urea and the unmodified activated carbon were subsequently selected for dioxin adsorption experiments using a dioxin generation and adsorption system. AC600 showed the highest adsorption efficiency for dioxins, reaching 97.65%, based on toxicity equivalents. Although AC800 has poor pore properties, it has more pyridine and pyrrole groups than AC600. Consequently, the efficiency of AC800 at adsorbing low-concentration dioxins reached 85.24% based on toxicity equivalents. Overall, this study describes two mechanisms for effectively modifying activated carbon with urea based on (1) optimizing the pore structure of activated carbon and (2) incorporating nitrogen.
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Carbón Orgánico , Dioxinas , Adsorción , Carbón Mineral , UreaRESUMEN
Nanomaterials have received increasing attentions owing to their potential hazards to the environment and human health; however, the multi-generational toxicity of graphene oxide under consecutive multi-generational exposure scenario still remains unclear. In the present study, Caenorhabditis elegans as an in vivo model organism was employed to explore the multi-generational toxicity effects of graphene oxide and the underlying mechanisms. Endpoints including development and lifespan, locomotion behaviors, defecation cycle, brood sizes, and oxidative response were evaluated in the parental generation and subsequent five filial generations. After continuous exposure for several generations, worms grew smaller and lived shorter. The locomotion behaviors were reduced across the filial generations and these reduced trends were following the impairments of locomotion-related neurons. In addition, the extended defecation cycles from the third filial generation were in consistency with the relative size reduction of the defecation related neuron. Simultaneously, the fertility function of the nematode was impaired under consecutive exposure as reduced brood sizes and oocytes numbers, increased apoptosis of germline, and aberrant expression of reproductive related genes ced-3, ced-4, ced-9, egl-1 and ced-13 were detected in exposed worms. Furthermore, the antioxidant enzyme, SOD-3 was significantly increased in the parent and filial generations. Thus, continuous multi-generational exposure to graphene oxide caused damage to the neuron development and the reproductive system in nematodes. These toxic effects could be reflected by indicators such as growth inhibition, shortened lifespan, and locomotion behavior impairment and induced oxidative response.
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Proteínas de Caenorhabditis elegans , Grafito , Animales , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Grafito/toxicidad , Longevidad , ReproducciónRESUMEN
BACKGROUND: Undergraduate medical (UM) students faced the difficulties inherent in medical careers due to the coronavirus (COVID-19) outbreak. Thus, imperative containment measures might affect UM students' career intentions. Information on the factors that may be associated with these students' career change intentions is limited. METHODS: We conducted a cross-sectional survey in August 2020 to investigate the impact of the COVID-19 pandemic on career intention and the associated factors in UM students. Univariate analyses and logistic regression analysis were performed to identify said factors. RESULTS: A total of 2040 medical students from the Hubei University of Medicine were surveyed. Univariate analyses showed that grade, attitude towards healthcare, and the degree of the COVID-19 pandemic's impact on the students' lives were associated with changes in career choice (P<0.05). Logistic regression analysis showed that Grade 2, Grade 5, attitude towards a medical career, and having relatives with a medical background were associated with changes in career choice. The degree of the COVID-19 pandemic's impact was a common and significant factor associated with career preference, career perspective, and ideal workplace. CONCLUSIONS: Changes in career intentions were particularly influenced by grade, attitude towards being a health worker, and the degree of COVID-19's impact on the participants' lives. Treating large-scale public health emergencies rationally, setting up correct views of occupation choice, and building reasonable career planning may reduce the loss of medical talent.
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COVID-19 , Estudiantes de Medicina , COVID-19/epidemiología , Selección de Profesión , Estudios Transversales , Humanos , Intención , Ocupaciones , Pandemias , SARS-CoV-2 , Encuestas y CuestionariosRESUMEN
The preparation of clean fuel or CO2 adsorbents using industrial and domestic garbage is an alternative way of meeting global energy needs and alleviating environmental problems. Herein, H2-mixed CH4 fuel and CaO-based CO2 sorbent were first prepared in one pot by the mechanochemical reaction of pretreated clamshell or eggshell wastes (carbon and calcium source) with calcium hydride (hydrogen source) at room temperature. In the above reactions, CH4 was the sole hydrocarbon product, and its yield reached 78.23%. The H2/CH4 ratio of the produced H2-mixed CH4 fuel was tunable according to the need by changing the reaction conditions. It is inspiring that the simultaneously formed solid CaO/carbon products were efficient CaO-based sorbents, which possessed a higher CO2 adsorption capacity (49.81-58.74 wt.%) at 650 °C and could maintain good adsorption stability in 30 carbonation/calcination cycles (average activity loss per cycle of only 1.6%). The three achievements of the idea are that it can simultaneously eliminate clamshell or eggshell wastes, obtain valuable clean fuel, and acquire efficient CaO-based sorbents.
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Compuestos de Calcio , Óxidos , Adsorción , Animales , Calcio , Carbono , Dióxido de Carbono , Cáscara de Huevo , Hidrogenación , TemperaturaRESUMEN
STUDY OBJECTIVE: In 2018, the Laparoscopic Approach to Cervical Cancer trial reported that patients undergoing minimally invasive surgery for cervical cancer (CC) had poorer outcomes than patients undergoing open surgery. Several hypotheses have been made to explain the results. We aimed to investigate whether laparoscopic procedures and use of a uterine manipulator increase the risk of lymphovascular space invasion (LVSI) in early-stage CC. DESIGN: A retrospective study. SETTING: A Chinese women's and children's hospital. PATIENTS: Patients with early-stage CC who underwent radical hysterectomy in West China Second University Hospital between April 2019 and May 2020. INTERVENTIONS: Laparoscopic surgery (with uterine manipulator and uterine manipulator-free) and open surgery. MEASUREMENTS AND MAIN RESULTS: A total of 979 patients diagnosed with CC were registered in West China Second University Hospital for surgical treatment. Of these, 525 patients underwent laparoscopic surgery and 454 patients underwent open surgery. In total, 735 patients with early-stage cancer underwent radical hysterectomy and pelvic lymphadenectomy, including 357 by laparoscopic surgery and 378 by open surgery. For those who underwent radical hysterectomy and pelvic lymphadenectomy, the incidence of LVSI was 48.41% and 47.34% in laparoscopic and open groups, respectively (pâ¯=â¯.771). After 1:1 propensity score matching with age, International Federation of Gynecology and Obstetrics stage, pathology, and tumor size, the incidence of LVSI was 45.54% and 51.79% in laparoscopic and open groups, respectively (pâ¯=â¯.186). Subdividing the laparoscopic group into uterine manipulator and uterine manipulator-free groups, the incidence of LVSI was 45.22% and 48.35%, respectively (pâ¯=â¯.580). After propensity score matching with age, International Federation of Gynecology and Obstetrics stage, pathology, and tumor size, the incidence of LVSI was 45.78% and 55.42% in these 2 groups, respectively (pâ¯=â¯.214). Multiple factor analysis revealed that lymph node metastasis and deep stromal invasion were associated with LVSI (p value <.05 in both groups). CONCLUSION: The surgical approach and use of a uterine manipulator are not associated with LVSI in surgery for early-stage CC. Lymph node metastasis and deep stromal invasion are associated with LVSI.
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Laparoscopía , Neoplasias del Cuello Uterino , Femenino , Humanos , Histerectomía , Escisión del Ganglio Linfático , Estadificación de Neoplasias , Estudios Retrospectivos , Neoplasias del Cuello Uterino/patología , Neoplasias del Cuello Uterino/cirugíaRESUMEN
Elevated arginase type II (Arg-II) associates with higher grade tumors. Its function and underlying molecular mechanisms in melanoma remain elusive. In the present study, we observed a significantly higher frequency of Arg-II expression in melanoma of patients with metastasis than those without metastasis. Silencing Arg-II in two human melanoma cell lines slowed down the cell growth, while overexpression of native but not a catalytically inactive Arg-II promoted cell proliferation without affecting cell death. Treatment of cells with arginase inhibitor also reduced melanoma cell number, demonstrating that Arg-II promotes melanoma cell proliferation dependently of its enzymatic activity. However, results from silencing Arg-II or overexpressing native or the inactive Arg-II as well as treatment with arginase inhibitor showed that Arg-II promotes melanoma metastasis-related processes, such as melanoma cell migration and adhesion on endothelial cells, independently of its enzymatic activity. Moreover, the treatment of the cells with STAT3 inhibitor suppressed Arg-II-promoted melanoma cell migration and adhesion. Furthermore, catalase, but not superoxide dismutase, prevented STAT3 activation as well as increased melanoma cell migration and adhesion induced by overexpressing native or the inactive Arg-II. Taken together, our study uncovers both activity-dependent and independent mechanisms of Arg-II in promoting melanoma progression. While Arg-II enhances melanoma cell proliferation through polyamine dependently of its enzymatic activity, it promotes metastasis-related processes, that is, migration and adhesion onto endothelial cell, through mitochondrial H2 O2 -STAT3 pathway independently of the enzymatic activity. Suppressing Arg-II expression rather than inhibiting its enzymatic activity may, therefore, represent a novel strategy for the treatment of melanoma.
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Arginasa/genética , Inhibidores Enzimáticos/farmacología , Melanoma/tratamiento farmacológico , Factor de Transcripción STAT3/genética , Animales , Arginasa/antagonistas & inhibidores , Adhesión Celular/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Endoteliales/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Peróxido de Hidrógeno/metabolismo , Melanoma/genética , Transducción de Señal/efectos de los fármacosRESUMEN
BACKGROUND: To evaluate the effect of clinicopathologic factors on the prognosis and fertility outcomes of BOT patients. METHODS: We performed a retrospective analysis of BOT patients who underwent surgical procedures in West China Second University Hospital from 2008 to 2015. The DFS outcomes, potential prognostic factors and fertility outcomes were evaluated. RESULTS: Four hundred forty-eight patients were included; 52 recurrences were observed. Ninety-two patients undergoing FSS achieved pregnancy. No significant differences in fertility outcomes were found between the staging and unstaged surgery groups. Staging surgery was not an independent prognostic factor for DFS. Laparoscopy resulted in better prognosis than laparotomy in patients with stage I tumours and a desire for fertility preservation. CONCLUSION: Patients with BOT fail to benefit from surgical staging. Laparoscopy is recommended for patients with stage I disease who desire to preserve fertility. Physicians should pay more attention to risk of recurrence in patients who want to preserve fertility.
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Preservación de la Fertilidad/métodos , Laparoscopía/efectos adversos , Recurrencia Local de Neoplasia/epidemiología , Tratamientos Conservadores del Órgano/métodos , Neoplasias Ováricas/diagnóstico , Ovariectomía/efectos adversos , Adulto , China/epidemiología , Supervivencia sin Enfermedad , Femenino , Preservación de la Fertilidad/efectos adversos , Preservación de la Fertilidad/estadística & datos numéricos , Humanos , Laparoscopía/métodos , Laparoscopía/estadística & datos numéricos , Persona de Mediana Edad , Recurrencia Local de Neoplasia/prevención & control , Estadificación de Neoplasias , Tratamientos Conservadores del Órgano/efectos adversos , Tratamientos Conservadores del Órgano/estadística & datos numéricos , Neoplasias Ováricas/mortalidad , Neoplasias Ováricas/patología , Neoplasias Ováricas/cirugía , Ovariectomía/métodos , Ovariectomía/estadística & datos numéricos , Ovario/patología , Ovario/cirugía , Embarazo , Índice de Embarazo , Pronóstico , Estudios Retrospectivos , Adulto JovenRESUMEN
We request that the following corrections be made in our article.
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BACKGROUND: Adipose tissue inflammation occurs not only in obesity but also in aging and is mechanistically linked with age-associated diseases. Studies show that ablation of the l-arginine-metabolizing enzyme arginase-II (Arg-II) reduces adipose tissue inflammation and improves glucose tolerance in obesity. However, the role of Arg-II in aging adipose tissue inflammation is not clear. OBJECTIVE: This study investigated the role of Arg-II in age-associated adipose tissue inflammation. METHODS: Visceral adipose tissues of young (3-6 months) and old (20-24 months) wild-type (WT) and Arg-II-/- mice were investigated. Immunofluorescence confocal microscopy was performed for analysis of macrophage accumulation and cellular localization of arginase and cytokines; expression of arginase and cytokines was analyzed by qRT-PCR or immunoblotting or ELISA; activation of mitogen-activated protein kinases in adipose tissues was analyzed by immunoblotting; and arginase activity was measured by colorimetric determination of urea production. RESULTS: In the old WT mice, there is more macrophage accumulation in the visceral adipose tissues than in Arg-II knockout animals. An age-associated increase in arginase activity and Arg-II expression in adipose tissues of WT mice is observed. Arg-II knockout enhances Arg-I expression and activity, but inhibits interleukin (IL)-6 expression and secretion and reduces active p38mapk in aging adipose tissue macrophages and stromal cells. Treatment of aging adipose tissues of WT mice with a specific p38mapk inhibitor SB203580 reduces IL-6 secretion. CONCLUSIONS: Arg-II promotes IL-6 production in aging adipose tissues through p38mapk. The results suggest that targeting Arg-II or inhibiting p38mapk could be beneficial in reducing age-associated adipose tissue inflammation.
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Tejido Adiposo/metabolismo , Envejecimiento/metabolismo , Arginasa/metabolismo , Inflamación/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Tejido Adiposo/química , Animales , Arginasa/genética , Femenino , Inflamación/complicaciones , Interleucina-6/metabolismo , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Obesidad/complicaciones , Obesidad/metabolismoRESUMEN
PURPOSE: Surgical procedures, histological subtypes, and surgical approaches are involved in the recurrence of borderline ovarian tumors (BOTs), but whether those three factors affect relapse remains controversial. This study aimed to explore the effects of surgical procedures, histological subtypes, and surgical approaches on the relapse and pregnancy rates of BOT after fertility-preserving surgery (FPS) according to the patients' characteristics. METHODS: A systematic search of PubMed, Embase, and the Cochrane library was conducted from their inception to November 2018. Studies that investigated the impact of surgical procedures, histological subtypes, and surgical approaches on the relapse and pregnancy rates in patients with BOT after FPS were eligible. The pooled odds ratios (ORs) with the corresponding 95% confidence intervals (CIs) were calculated using the random-effects model. RESULTS: Thirty-five studies involving a total of 2921 patients with BOT after FPS were included. The pooled ORs indicated that the risk of relapse was significantly increased in patients who underwent unilateral cystectomy or with serous BOT. There was no significant difference between laparoscopy and laparotomy on the risk of relapse. Surgical procedures, histological subtypes, and surgical approaches did not influence pregnancy rates. CONCLUSIONS: Patients who underwent unilateral cystectomy or with serous BOT presented an excess risk of relapse after FPS, but the surgical approach did not affect the risk of relapse. The pregnancy rate is not affected by surgical procedures, histological subtypes, and surgical approaches.
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Cistectomía/métodos , Preservación de la Fertilidad/métodos , Infertilidad Femenina/prevención & control , Neoplasias Quísticas, Mucinosas y Serosas/cirugía , Neoplasias Ováricas/cirugía , Ovariectomía/métodos , Adulto , Femenino , Humanos , Laparoscopía/métodos , Laparotomía , Recurrencia Local de Neoplasia/patología , Neoplasias Quísticas, Mucinosas y Serosas/patología , Neoplasias Ováricas/patología , Ovariectomía/efectos adversos , Embarazo , Resultado del Embarazo , Índice de Embarazo , Resultado del TratamientoRESUMEN
PURPOSE: To determine whether or not the risk of recurrence of uterine leiomyoma (UL) was different between laparoscopic myomectomy (LM) and open myomectomy (OM). METHODS: This study combined a multicenter cohort study with a meta-analysis. The cohort study included women aged 18-44 years with 1-3 leiomyomas who underwent LM or OM for UL at one of three teaching hospitals. The meta-analysis included trials comparing recurrence rates of UL between OM and LM. RESULTS: A total of 396 patients (LM: n = 83; OM: n = 313) were recruited in the cohort study. For women aged 18-44 years with 1-3 leiomyomas, surgical approach (LM vs. OM) was not an independent risk factor of UL recurrence (31.3% vs. 34.2%, P = 0.571), and the reoperation rate of UL was similar between the LM and OM (2.4% vs. 4.2%, P = 0.726). A total of 2566 patients were meta-analyzed. The recurrence of UL was similar between LM and OM when the patients had ≤ 5 leiomyomas (OR 1.10; 95% CI 0.76-1.61; P = 0.610; I2 = 0%), while the recurrence rate in LM group was higher when the patients had > 5 leiomyomas (OR 1.50; 95% CI 1.14-1.97; P = 0.004; I2 = 38%). CONCLUSION: From the meta-analysis, the recurrence rate of UL was similar between LM and OM when the patients had ≤ 5 leiomyomas, while the recurrence of LM was higher when the number of leiomyomas was > 5. The cohort study partially supported this conclusion and it further proved the reoperation rate of UL was also similar among women aged 18-44 years with ≤ 3 leiomyomas. Therefore, OM should be considered for patients with > 3 or 5 leiomyomas if myomectomy has already been chosen.
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Laparoscopía/métodos , Leiomioma/etiología , Miomectomía Uterina/efectos adversos , Neoplasias Uterinas/etiología , Adolescente , Adulto , Estudios de Cohortes , Femenino , Humanos , Leiomioma/cirugía , Recurrencia Local de Neoplasia/cirugía , Estudios Retrospectivos , Miomectomía Uterina/métodos , Adulto JovenRESUMEN
This research introduces a new multifunction biquad filter based on voltage mode (VM) current-feedback operational amplifier (CFOA) and a fully uncoupled quadrature oscillator (QO) based on the proposed VM multifunction biquad filter. The proposed VM multifunction biquad filter has high impedance to the input voltage signal, and uses three CFOAs as active components, while using four resistors and two grounded capacitors as passive components. The VM CFOA-based multifunction biquad filter realizes band-reject, band-pass, and low-pass transfer functions at high-input impedance node simultaneously, which has the feature of easy cascading in VM operation without the need for additional voltage buffers. Additionally, the filter control factor parameter pole frequency (ωo) and quality factor (Q) of the proposed VM multifunction biquad filter can be independently set by varying different resistors. By slightly modifying the VM multifunction biquad filter topology, a VM fully-uncoupled QO is easily obtained. The difference from the previous VM CFOA-based multifunction biquad filter is that the proposed VM CFOA-based multifunction biquad filter can be independently controlled by the filter control factor parameters, ωo and Q. The proposed VM CFOA-based multifunction biquad filter can be transformed into a VM QO with fully-uncoupled adjustable of the oscillation condition and the oscillation frequency. The oscillation condition and the oscillation frequency can be fully-uncoupled and controlled by varying two sets of completely different resistors. The proposed VM fully-uncoupled QO solves the amplitude instability. The constant amplitude ratio of two quadrature sinusoidal waveforms can be realized when tuning FO. PSpice simulation and experimental results prove the performances of the proposed VM multifunction filter and VM fully-uncoupled QO. Simulation and experimental results confirm the theoretical analysis of the proposed circuits.
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2,4,6-Tri(4-pyridyl)-1,3,5-triazine (tpt) is a widely used ligand for functional coordination compounds. In this work, tpt has shown unprecedented photochromism in the crystalline state. Experimental and theoretical data has revealed that the photocoloration of tpt very likely originates from intramolecular charge separation and the formation of a triplet diradical product. This finding demonstrates a new simple, neutral photochromic molecule and endows the tpt molecule and related compounds with potential optical applications.
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Type-II l-arginine:ureahydrolase, arginase-II (Arg-II), is abundantly expressed in the kidney. The physiologic role played by Arg-II in the kidney remains unknown. Herein, we report that in mice that are deficient in Arg-II (Arg-II-/-), total and membrane-associated aquaporin-2 (AQP2) protein levels were significantly higher compared with wild-type (WT) controls. Water deprivation enhanced Arg-II expression, AQP2 levels, and membrane association in collecting ducts. Effects of water deprivation on AQP2 were stronger in Arg-II-/- mice than in WT mice. Accordingly, a decrease in urine volume and an increase in urine osmolality under water deprivation were more pronounced in Arg-II-/- mice than in WT mice, which correlated with a weaker increase in plasma osmolality in Arg-II-/- mice. There was no difference in vasopressin release under water deprivation conditions between either genotype of mice. Although total AQP2 and phosphorylated AQP2-S256 levels (mediated by PKA) in kidneys under water deprivation conditions were significantly higher in Arg-II-/- mice compared with WT animals, there is no difference in the ratio of AQP2-S256:AQP2. In cultured mouse collecting duct principal mCCDcl1 cells, expression of both Arg-II and AQP2 were enhanced by the vasopressin type 2 receptor agonist, desamino- d-arginine vasopressin (dDAVP). Silencing Arg-II enhanced the expression and membrane association of AQP2 by dDAVP without influencing cAMP levels. In conclusion, in vivo and in vitro experiments demonstrate that Arg-II negatively regulates AQP2 and the urine-concentrating capability in kidneys via a mechanism that is not associated with the modulation of the cAMP pathway.-Huang, J., Montani, J.-P., Verrey, F., Feraille, E., Ming, X.-F., Yang, Z. Arginase-II negatively regulates renal aquaporin-2 and water reabsorption.
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Acuaporina 2/metabolismo , Arginasa/metabolismo , Túbulos Renales Colectores/metabolismo , Agua/metabolismo , Animales , Acuaporina 2/genética , Arginasa/genética , Arginina Vasopresina/farmacología , Línea Celular , AMP Cíclico/genética , AMP Cíclico/metabolismo , Túbulos Renales Colectores/citología , Ratones , Ratones Noqueados , Receptores de Vasopresinas/agonistas , Receptores de Vasopresinas/genética , Receptores de Vasopresinas/metabolismoRESUMEN
Titanium ions significantly promote plant growth, but the mechanism is still unclear. Cut flowers are ideal materials for the study of plant growth and senescence. In this study, freshly cut Gerbera jamesonii were used to study the effects of titanium ions (8 mg/L) on the flower longevity. Flowering observation showed that the gerbera vase life was significantly prolonged in the presence of titanium ions. Plate colony counts showed that the amounts of bacteria in the vase solution of the control group were approximately 1700 times more than that of titanium ion treatment group. High-throughput sequencing was used to determine the sequences of 16S rRNA gene V3-V4 variable regions of the vase solutions to analyze bacterial species, their average proportions, and absolute abundance. The results showed that the titanium ions reduced the entire bacterial counts as well as altered the absolute abundance of different bacterial species in the vase solution. The most prevalent bacteria were mainly Enterobacteriaceae, Pseudomonas veronii, Pseudomonas sp., Delftia sp., Agrobacterium sp., Sphingobacterium multivorum, Acinetobacter johnsonii, and Clostridiaceae. In combination with plate colony counts, we demonstrated that all the bacterial growths were significantly inhibited by titanium ions, regardless of their average proportions increased or decreased. These results showed that titanium ions could extend effectively the longevity of gerberas and possess the broad-spectrum antibacterial properties. This study provides a basis for further mechanism exploration of titanium ions action and its applications in cut flower preservation and agricultural production.
Asunto(s)
Bacterias/metabolismo , Titanio/metabolismo , Microbiología del Agua , Asteraceae/crecimiento & desarrollo , Bacterias/clasificación , Bacterias/efectos de los fármacos , Flores/crecimiento & desarrollo , Iones/metabolismo , ARN Bacteriano/análisis , ARN Ribosómico 16S/análisisRESUMEN
AIMS: Diabetic nephropathy (DN) is a severe microvascular complication frequently associated with type 1 and type 2 diabetes mellitus. The objective of this study was to estimate the effect between Apa I, Bsm I, Fok I and Taq I polymorphisms of the vitamin D receptor (VDR) gene and DN susceptibility. METHODS: Eligible case-control studies published updated to March 2017 were searched. The odds ratio (OR) and 95% confident intervals (CI) were used to calculate the strength of effect. RESULTS: Twelve articles were finally screened out, including 3954 diabetic patients and 1248 healthy controls. When compared with the diabetic patients without nephropathy, our results found that only the Bsm I polymorphism was associated with increased risk of DN under the allelic model (B vs. b: OR = 1.51, 95% CI = 1.03-2.20, P = 0.04) and dominant model (BB + Bb vs. bb: OR = 1.52, 95% CI = 1.00-2.31, P = 0.05). When compared with the healthy controls, our results showed that the Bsm I polymorphism was associated with the DN susceptibility under the allelic model (B vs. b: OR = 1.80, 95% CI = 1.12-2.91, P = 0.02), the homogeneous model (BB vs. bb: OR = 1.43, 95% CI = 1.03-1.98, P = 0.03), and the domain model (BB + Bb vs. bb: OR = 1.80, 95% CI = 1.06-3.05, P = 0.03); the Taq I variant was associated with increased risk of DN only under the heterogeneous model (Tt vs. tt: OR = 2.29, 95% CI = 1.04-5.03, P = 0.04). CONCLUSION: Our results suggested that B allele, and BB + Bb genotypes of Bsm I variant, Tt genotype of Taq I variant might be risk factors for DN. Future researches are still needed to identify our results.