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1.
Int J Clin Oncol ; 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38652434

RESUMEN

BACKGROUND: Multivisceral en bloc resection with the ipsilateral kidney is commonly performed in patients with retroperitoneal liposarcoma (RLPS). We evaluated the effect of nephrectomy on short- and long-term outcomes in patients with RLPS. METHODS: Data from a prospectively maintained database of the Peking University Cancer Hospital Sarcoma Center between April 2011 and August 2022 were analyzed. We classified the RLPS patients who underwent surgery into nephrectomy group (NP) and non-nephrectomy group (non-NP). Patients were matched using a 1:1 propensity score to eliminate baseline differences between groups. Postoperative renal function outcomes, major morbidity, and mortality were analyzed to compare short-term outcomes after nephrectomy. Differences in local recurrence-free survival (LRFS) and overall survival (OS) were compared by Kaplan-Meier analysis with respect to oncological benefits. RESULTS: In the matched cohort, patients in the NP group had significantly higher postoperative eGFR and CKD stages, but none required dialysis. Patients between NP and non-NP had a comparable major morbidity (p = 0.820) and 60-day mortality (p = 0.475). Patients in the NP group had a higher 5-year LRFS rates than those in the non-NP group (34.5 vs. 17.8%, p = 0.015), and similar 5-year OS rates (52.4 vs. 47.1%, p = 0.401). Nephrectomy was an independent risk factor for LRFS, but not for major morbidity or OS. CONCLUSIONS: RLPS resection with nephrectomy is related to a mild progression of renal impairment; however, dialysis is rare. En bloc nephrectomy for complete resection of RLPS is safe and improves local control.

2.
Environ Sci Pollut Res Int ; 31(12): 18856-18870, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38351356

RESUMEN

Solid waste management is a critical issue worldwide. Effectively utilizing these solid waste resources presents a viable solution. This study focuses on Iron ore tailings (IOTs), a solid waste generated during iron ore processing, which can be used as supplementary cementitious materials (SCMs) but have low reactivity, hindering their large-scale application in concrete production. To address this, ternary SCMs were prepared using ceramic powder (CP) and steel slag (SS) to enhance the performance of concrete incorporating IOTs. The study found that the synergistic effect of CP and SS significantly improved the compressive strength of concrete, with a notable increase of up to 21% compared to concrete with IOTs alone. Mercury intrusion porosimetry (MIP) and backscattering electron (BSE) analyses revealed that the ternary SCMs significantly optimized the characteristics of the interfacial transition zone (ITZ), which in turn enhanced the compressive properties of the concrete. This contributed to maintaining the structural integrity of the concrete, even amidst variations in the pore structure. Importantly, the incorporation of ternary SCMs led to a 23% reduction in carbon emissions, from 400.01 kg CO2/m3 to 307.48 kg CO2/m3, and elevated eco-strength efficiency from 0.1 to 0.14. The study highlights the role of multi-material synergy in developing composite SCMs systems, fostering the sustainable advancement of green building materials.


Asunto(s)
Dióxido de Carbono , Acero , Polvos , Residuos Sólidos , Cerámica , Hierro
3.
Intractable Rare Dis Res ; 13(1): 51-56, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38404729

RESUMEN

To analyze the outcome in patients who have undergone multivisceral resection (MVR) for locally advanced gastrointestinal stromal tumors (GISTs), and identify the risk factors for tumor recurrence and postoperative morbidity. Sixty-four patients who operated for locally advanced GISTs with MVR in PPeking University Cancer Hospital Sarcoma Center (PUCHSC) between 2013 and 2021 were identified. Clinicopathologic characteristics, surgical outcomes, recurrence, and 5-year recurrence-free and overall survival were evaluated. The mean age of the patients was 60 years. Mean tumor size was 11.1 cm. Complete resection was achieved in all patients. The estimated 5-year recurrence-free and overall survival were 86.6% and 90.0%, respectively. Independent factor of recurrence following surgery was mitotic count on multivariate analysis. Overall postoperative morbidity was 53.1% (n = 34). Severe morbidity was 21.9% (n = 14). The most common severe complication was clinically relevant pancreatic fistula (n = 12, 18.8%), followed by anastomotic leakage (n = 4, 6.3%) and Intraabdominal abscess (n = 4, 6.3%). Multivariate analysis showed that preoperative imatinib therapy could reduce overall morbidity. Long operation time, combined colectomy and pancreatectomy were independent risk factors for postoperative severe morbidity. Compared to partial pancreatectomy, pancreaticoduodenectomy (PD) was significantly increased the incidence of severe morbidity. In conclusion, compared to systemic therapy alone, the outcome of locally advanced GISTs after MVR was more favorable. Despite the high overall morbidity, the postoperative severe morbidity and mortality of MVR were acceptable. Preoperative imatinib therapy should be recommended whenever possible. Combined pancreatectomy and colectomy are associated with significant postoperative severe morbidities. PD should be thoroughly discussed and be subject to MDT approach before surgery.

4.
Sensors (Basel) ; 24(2)2024 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-38257435

RESUMEN

We propose a humidity sensor using an excessively tilted fiber grating (Ex-TFG) coated with agarose fabricated using femtosecond laser processing. The processed grating showcases remarkable differentiation between TE and TM modes, achieving an exceptionally narrow bandwidth of approximately 1.5 nm and an impressive modulation depth of up to 15 dB for both modes. We exposed the agarose-coated TFG sensor to various relative humidity levels and monitored the resonance wavelength to test its humidity sensing capability. Our findings demonstrated that the sensor exhibited a rapid response time (2-4 s) and showed a high response sensitivity (18.5 pm/%RH) between the humidity changes and the resonant wavelength shifts. The high sensitivity, linearity, repeatability, low hysteresis, and excellent long-term stability of the TFG humidity sensor, as demonstrated in our experimental results, make it an attractive option for environmental monitoring or biomedical diagnosis.

5.
Altern Ther Health Med ; 29(8): 882-891, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37708561

RESUMEN

Nephrotic syndrome, a common kidney disease syndrome in children, has triggered extensive clinical research to identify safe and effective treatments. Qingxin Lianzi Drink, as a traditional Chinese medicine prescription, has been paid more and more attention in the treatment of nephrotic syndrome in children. Its main ingredients include Shilotus meat, scutellaria skullcap and ground bone skin, etc. These ingredients have the effects of clearing heat and detoxifying, reducing swelling and water, and nourishing liver and kidney. In the treatment of nephrotic syndrome in children, Qingxin Lianzi Drink can play a role in many ways: first, it can inhibit inflammatory response, reduce glomerular inflammatory damage, relieve proteinuria and other symptoms; Secondly, the ingredients such as stone lotus meat can promote the excretion of waste and water in the body, reduce edema and edema and other symptoms; Finally, scutellaria and other ingredients can nourish liver and kidney and promote the recovery of liver and kidney function. At present, a large number of studies have found that Qingxin Lianzi Drink has obvious effect on chronic kidney disease. In addition, Qingxin Lianzi Drink as a natural therapy, compared with traditional western medicine treatment, more safe, natural and effective, has been widely concerned. Therefore, Qingxin Lianzi Drink in the treatment of children with nephrotic syndrome of the mechanism of action and efficacy evaluation of the study is of great significance. In this paper, combining the pathogenesis and treatment status of nephrotic syndrome in children, the mechanism of Qingxin Lianzi Drink in the treatment of nephrotic syndrome is explored, which can better understand its effectiveness in the treatment of nephrotic syndrome in children, and provide scientific basis for its application in clinical practice.


Asunto(s)
Síndrome Nefrótico , Niño , Humanos , Síndrome Nefrótico/tratamiento farmacológico , Síndrome Nefrótico/diagnóstico , Riñón , Medicina Tradicional China , Edema , Agua
6.
Small ; 19(48): e2304258, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37525327

RESUMEN

How to mildly structure a high intrinsic activity and stable catalytic electrode to realize long-term catalytic water splitting to produce hydrogen at a wide range of pH values at industrial high current is a challenge. Herein, this work creatively proposes to prepare industrial-grade catalytic electrodes with high efficiency and stability at high current density through carbon quantum dots (CDs) modification nickel sulfide on hydrophilic flexible filter paper via one-step mild chemical plating (denoted as CDs-Ni3 S2 @HFP). The intrinsic activity and surface area, electron transfer ability, and corrosion resistance of Ni3 S2 material are increased due to the regulation, homogenous, and high concentration doping of CDs. The overpotential of the flexible catalytic electrode is only 30, 35, and 87 mV in 1 m KOH, simulated seawater (1 m KOH + 0.5 m NaCl), and neutral electrolyte (0.5 m PBS) at a current density of 10 mA cm-2 . More attractively, the CDs-Ni3 S2 @HFP electrode achieves over 500 h of efficient and stable catalysis at industrial high current density (500 mA cm-2 ). Due to the advantages of mild, universal, and large-area preparation of catalytic materials, this work provides technical support for flexible catalytic electrodes in efficient catalysis toward water splitting, energy storage, and device preparation.

7.
Opt Lett ; 48(7): 1922-1925, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-37221800

RESUMEN

A microbubble-probe whispering gallery mode resonator with high displacement resolution and spatial resolution for displacement sensing is proposed. The resonator consists of an air bubble and a probe. The probe has a diameter of ∼5 µm that grants micron-level spatial resolution. Fabricated by a CO2 laser machining platform, a universal quality factor of over 106 is achieved. In displacement sensing, the sensor exhibits a displacement resolution of 74.83 pm and an estimated measurement span of 29.44 µm. As the first microbubble probe resonator for displacement measurement, the component shows advantages in performance, and exhibits a potential in sensing with high precision.

8.
Ann Transl Med ; 11(5): 212, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-37007540

RESUMEN

Background: Conventional chemotherapy has limited therapeutic effects in retroperitoneal soft tissue sarcomas (RSTs), while anlotinib emerged as a novel multi-target tyrosine kinase inhibitor (TKI) for sarcomas. TKIs in combination with immunotherapy have demonstrated clinical activity in a variety of solid tumors. This study retrospectively analyzed the efficacy and safety of anlotinib plus camrelizumab for the treatment of RSTs. Methods: Patients with RSTs who received anlotinib plus camrelizumab at Peking University Cancer Hospital Sarcoma Center were enrolled. Response assessment was conducted every 3 cycles of treatment according to response evaluation criteria in solid tumors version 1.1 (RECIST v1.1). Treatment-related adverse events (TRAEs) were evaluated by Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Patients who had at least 1 response evaluation were analyzed. Results: In all, 57 RSTs cases including 35 males and 22 females were analyzed, with a median age of 55 years. The pathological subtypes included 38 cases of L-sarcoma (liposarcoma and leiomyosarcoma), and 19 cases of non-L-sarcoma. Two patients (3.5%) had complete response (CR) and 13 patients (22.8%) had partial response (PR), with an objective response rate (ORR) of 26.3%. There were 31 (54.4%) and 11 (19.3%) patients with stable and progressive disease, respectively, with a disease control rate of 80.7%. Patients with non-L-sarcoma had a significantly better response rate than those with L-sarcoma (ORR: 52.6% vs. 13.2%; P=0.0031). After a median follow-up of 15.8 months, the median progression-free survival (PFS) was 9.1 months, with 3- and 6-month PFS rates of 83.6% and 60.8%, respectively. Patients with non-L-sarcoma had a significantly longer median PFS than did those with L-sarcoma (median PFS: 11.1 vs. 6.3 months; P=0.0256). TRAEs occurred in 28 (49.1%) patients, and 13 (22.8%) patients had grade 3-4 TRAEs. Hypertension (24.6%), hypothyroidism (19.3%), and palmar-plantar erythrodysesthesia syndrome (12.3%) were the most common TRAEs. Conclusions: The combination of anlotinib and camrelizumab demonstrated possible therapeutic efficacy and safety in the treatment of RSTs, especially for non-L-sarcomas.

9.
J Geriatr Cardiol ; 20(2): 100-108, 2023 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-36910245

RESUMEN

OBJECTIVE: To determine the role of ascending aorta dilatation in the relationship between pulse pressure (PP) and left ventricular (LV) hypertrophy. METHODS: A total of 1556 Chinese elderly hypertensive patients were retrospectively studied. Transthoracic echocardiography was used to obtain the aortic and cardiac structure measurements. In addition, brachial blood pressure was measured, and total arterial compliance, systemic vascular resistance, arterial elastance, and end-systolic LV elastance were calculated. The participants were divided into four groups according to the status of ascending aortic diameter and PP. RESULTS: LV mass index increased in succession in the four groups, i.e., the group with the normal aorta and lower PP, with the normal aorta and higher PP, with aortic dilatation and lower PP, and with aortic dilatation and higher PP (P trend < 0.001). Total arterial compliance-1, arterial elastance, and end-systolic LV elastance were slightly higher in the individuals with normal aorta compared to those with aortic dilatation, regardless of PP being lower or higher (P < 0.01). Compared to the group with the normal aorta and lower PP, individuals with aortic dilatation had a significantly increased multivariable adjusted risk of LV hypertrophy, and higher PP further exacerbated this risk [aortic dilatation with lower PP (OR = 1.75, 95% CI: 1.01-3.04) and aortic dilatation with higher PP (OR = 3.42, 95% CI: 2.03-5.77)]. In the relation between PP and LV mass index (ß = 0.095, P < 0.001), -41.3% of the total effect was attributable to mediation by ascending aortic diameter (P < 0.0001). CONCLUSIONS: In Chinese elderly patients with hypertension, ascending aorta dilatation could reduce the influence of elevated PP on LV hypertrophy.

10.
J Hazard Mater ; 443(Pt B): 130306, 2023 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-36345065

RESUMEN

Prechlorination routinely applied for the treatment of algae-laden raw water has received extensive attention due to its influence on water quality and aquatic microbes. In this study, prechlorination experiments with different doses were conducted in sets of model raw water distribution systems. With the elevated dose of chlorine and prolonged hydraulic retention time (HRT), the ratio of intact algal cells decreased, and the stability of water enhanced. Dissolved organic carbon (DOC) and nitrogen (DON) increased when chlorine dose elevated from 0 to 0.5 mg/L but decreased with elevations from 0.5 to 2.0 mg/L, while UV254 showed a monotonically increasing tendency. DOC, DON and extracellular microcystin-LR increase initially and decrease thereafter with the prolonged HRT. Notably, the effects of prechlorination on extracellular polymeric substances aggregation behavior on pipe walls and microbial community composition was revealed, providing more profound understanding of the community dynamics in this engineered system. This study helped optimize strategies to improve the stability and efficiency of pretreatment of algae-laden water.


Asunto(s)
Cloro , Matriz Extracelular de Sustancias Poliméricas , Microcistinas , Biopelículas
11.
J Surg Oncol ; 127(4): 633-644, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36444482

RESUMEN

BACKGROUND AND OBJECTIVES: Resection of retroperitoneal sarcoma (RPS) en bloc with pancreas is challenging and controversial. This single-center retrospective study aimed to analyze the impact of pancreatic resection (PR) and its different types on short- and long-term outcomes in patients with RPS. METHODS: Data from 242 consecutive patients with RPS who underwent surgical treatment at the Peking University Cancer Hospital Sarcoma Center between January 2010 and February 2021 were analyzed. Out of these, 90 patients underwent PR, including pancreaticoduodenectomy (PD) in 31 and distal pancreatectomy (DP) in 59. RESULTS: Patients in the PR group had a higher major morbidity (37.8% vs. 14.5%) and mortality (8.9% vs. 1.3%) than those in the non-PR group, with a similar 5-year overall survival (OS) rate (46.9% vs. 53.6%). Patients in the PD and DP groups had a slight difference in major morbidity (48.4% vs. 32.2%), mortality (6.4% vs. 10.2%), and 5-year OS rates (43.3% vs. 49.3%). The PR type was not an independent risk factor for major morbidity or OS. CONCLUSIONS: PR in RPS resection was associated with increased morbidity and mortality with minimal influence on survival. Patients with RPS undergoing PD and DP showed slight differences in terms of safety and OS.


Asunto(s)
Neoplasias Pancreáticas , Neoplasias Retroperitoneales , Sarcoma , Humanos , Pancreatectomía , Estudios Retrospectivos , Sarcoma/cirugía , Neoplasias Retroperitoneales/cirugía , Resultado del Tratamiento , Neoplasias Pancreáticas/cirugía
12.
Sensors (Basel) ; 22(23)2022 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-36501770

RESUMEN

Nanomechanical resonators made from suspended graphene combine the properties of ultracompactness and ultrahigh detection sensitivity, making them interesting devices for sensing applications. However, nanomechanical systems can be affected by membrane stress. The present work developed an optomechanical resonator for thermal stress sensing. The proposed resonator consists of a section of hollow core fiber (HCF) and a trampoline graphene-Au membrane. An all-optical system that integrated optical excitation and optical detection was applied. Then, the resonance frequency of the resonator was obtained through this all-optical system. In addition, this system and the resonator were used to detect the membrane's built-in stress, which depended on the ambient temperature, by monitoring the resonance frequency shift. The results verified that the temperature-induced thermal effect had a significant impact on membrane stress. Temperature sensitivities of 2.2646 kHz/°C and 2.3212 kHz/°C were obtained when the temperature rose and fell, respectively. As such, we believe that this device will be beneficial for the quality monitoring of graphene mechanical resonators.

13.
Front Oncol ; 12: 950418, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36387243

RESUMEN

Background: Peritoneal sarcomatosis (PS) could occur in patients with retroperitoneal sarcomas (RPS). This study aimed to expand the understanding of PS on its characteristics and prognostic role, and develop a nomogram to predict its occurrence preoperatively. Methods: Data of 211 consecutive patients with RPS who underwent surgical treatment between 2011 and 2019 was retrospectively reviewed. First, the clinicopathological characteristics of PS were summarized and analyzed. Second, the disease-specific survival (DSS) and recurrence-free survival (RFS) of patients were analyzed to evaluate the prognostic role of PS. Third, preoperative imaging, nearly the only way to detect PS preoperatively, was combined with other screened risk factors to develop a nomogram. The performance of the nomogram was assessed. Results: Among the 211 patients, 49 (23.2%) patients had PS with an incidence of 13.0% in the primary patients and 35.4% in the recurrent patients. The highest incidence of PS occurred in dedifferentiated liposarcoma (25.3%) and undifferentiated pleomorphic sarcoma (25.0%). The diagnostic sensitivity of the preoperative imaging was 71.4% and its specificity was 92.6%. The maximum standardized uptake value (SUVmax) was elevated in patients with PS (P<0.001). IHC staining for liposarcoma revealed that the expression of VEGFR-2 was significantly higher in the PS group than that in the non-PS group (P = 0.008). Survival analysis (n =196) showed significantly worse DSS in the PS group than in non-PS group (median: 16.0 months vs. not reached, P < 0.001). In addition, PS was proven as one of the most significant prognostic predictors of both DSS and RFS by random survival forest algorithm. A nomogram to predict PS status was developed based on preoperative imaging combined with four risk factors including the presentation status (primary vs. recurrent), ascites, SUVmax, and tumor size. The nomogram significantly improved the diagnostic sensitivity compared to preoperative imaging alone (44/49, 89.8% vs. 35/49, 71.4%). The C-statistics of the nomogram was 0.932, and similar C-statistics (0.886) was achieved at internal cross-validation. Conclusion: PS is a significant prognostic indicator for RPS, and it occurs more often in recurrent RPS and in RPS with higher malignant tendency. The proposed nomogram is effective to predict PS preoperatively.

14.
ACS Appl Mater Interfaces ; 14(36): 41379-41388, 2022 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-36064308

RESUMEN

Optical fiber humidity sensors have sparked enormous interests in many fields because of their excellent features. However, it remains a great challenge to balance sensitivity, humidity response, temperature crosstalk, and wet hysteresis for real-world application. To overcome this trade-off, an optical fiber humidity sensor is developed here by coating functional graphene oxide (GO)/polyelectrolyte nanocomposite film on the excessively tilted fiber grating (ex-TFG), in which GO/polyelectrolyte nanocomposite film is employed for enhancing the hydrophilicity and accelerating the adsorption/desorption of water molecule, while the ex-TFG is utilized for improving the sensitivity of refractive index and eliminating the crosstalk of temperature. By this design, optical fiber humidity sensors achieve high sensitivity, rapid response and recovery, low hysteresis, and temperature crosstalk as well as excellent repeatability and stability in large relative humidity (RH) range. Our work provides a promising platform for effective RH monitoring systems that can be widely applied in rapid diagnostics, pharmacy, precision medicine, and so forth.

15.
Front Surg ; 9: 956384, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36157408

RESUMEN

The outcomes of patients with primary retroperitoneal sarcoma (RPS) are significantly superior to those with recurrence. En bloc resection of tumor and adjacent organs is recommended in primary RPS. However, whether en bloc resection of tumor and adjacent organs can benefit recurrent patients or some recurrent patients is unclear. We compared the outcomes of patients with primary RPS, first recurrence (RPS-Rec1), and ≥2 recurrences (≥RPS-Rec2) to evaluate the value and criteria for en bloc resection of tumor and adjacent organs in recurrent cases. We evaluated the safety of en bloc resection of tumor and adjacent organs by assessing operation time, blood loss volume, postoperative morbidities (POM), and efficacy by comparing local recurrence and peritoneal metastasis (LR-PM), distant metastasis, progression-free survival (PFS), and overall survival (OS). A total of 101, 47, and 30 patients with primary RPS, RPS-Rec1, and ≥RPS-Rec2 were included, respectively. Recurrent RPS invaded more adjacent organs and surrounding fat tissue than primary RPS. The operation time, amount of blood loss, incidence of grade III-V POM, LR-PM rate, PFS, and OS in the RPS-Rec1 group were similar to those of the primary group, both of which were significantly superior to those of the ≥RPS-Rec2 group. Macroscopically incomplete resection and high-grade RPS rather than first recurrence were independent risk factors for LR-PM, PFS, and OS. In conclusion, the safety and efficacy of en bloc resection of tumor and adjacent organs in RPS-Rec1 were comparable with those in primary RPS but significantly superior to those of ≥RPS-Rec2. For RPS-Rec1, comparable outcomes to patients with primary RPS can be achieved, particularly in those in whom a macroscopically complete resection is achieved.

16.
Sensors (Basel) ; 22(18)2022 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-36146172

RESUMEN

An all-fiber glucose sensor is proposed and demonstrated based on a helical intermediate-period fiber grating (HIPFG) produced by using a hydrogen/oxygen flame heating method. The HIPFG, with a grating length of 1.7 cm and a period of 35 µm, presents four sets of double dips with low insertion losses and strong coupling strengths in the transmission spectrum. The HIPFG possesses an averaged refractive index (RI) sensitivity of 213.6 nm/RIU nm/RIU in the RI range of 1.33-1.36 and a highest RI sensitivity of 472 nm/RIU at RI of 1.395. In addition, the HIPFG is demonstrated with a low-temperature sensitivity of 3.67 pm/°C, which promises a self-temperature compensation in glucose detection. In the glucose-sensing test, the HIPFG sensor manifests a detection sensitivity of 0.026 nm/(mg/mL) and a limit of detection (LOD) of 1 mg/mL. Moreover, the HIPFG sensor exhibits good stability in 2 h, indicating its capacity for long-time detection. The properties of easy fabrication, high flexibility, insensitivity to temperature, and good stability of the proposed HIPFG endow it with a promising potential for long-term and compact biosensors.


Asunto(s)
Fibras Ópticas , Refractometría , Glucosa , Hidrógeno , Oxígeno
17.
ACS Appl Mater Interfaces ; 14(34): 39211-39219, 2022 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-35994410

RESUMEN

Nanomechanical sensors made from suspended graphene are sensitive to pressure changes. However, these devices typically function by obtaining an electrical signal based on the static displacement of a suspended graphene membrane and so, in practice, have limited sensitivity and operational range. The present work demonstrates an optomechanical Au/graphene membrane-based gas pressure sensor with ultrahigh sensitivity. This sensor comprises a suspended Au/graphene membrane appended to a section of hollow-core fiber to form a sealed Fabry-Pérot cavity. In contrast to conventional nanomechanical pressure sensors, pressure changes are monitored via resonant sensing with an optical readout. A miniature pressure sensor based on this principle was able to detect an ultrasmall pressure difference of 1 × 10-7 mbar in the ultrahigh-vacuum region with a pressure range of 4.1 × 10-5 to 8.3 × 10-6 mbar. Furthermore, this pressure sensor can work over an extended pressure range of 7 × 10-6 mbar to 1000 mbar at room temperature, outperforming commercial pressure sensors. Similar results were obtained using both the fundamental and higher-order resonant frequencies but with the latter providing improved sensitivity. This sensor has a wide range of potential applications, including indoor navigation, altitude monitoring, and motion detection.

18.
Materials (Basel) ; 15(14)2022 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-35888354

RESUMEN

The increasing concern for decarbonization and sustainability in construction materials is calling for green binders to partially replace cement since its production is responsible for approximately 8% of global anthropogenic greenhouse gas emissions. Supplementary cementitious materials (SCMs), including fly ash, slag, silica fume, etc., can be used as a partial replacement for ordinary Portland cement (OPC) owing to reduced carbon dioxide emissions associated with OPC production. This study aims to investigate the sustainable use of waste oyster shell powder (OSP)-lithium slag (LS)-ground granulated blast furnace slag (GGBFS) ternary SCM system in green concrete. The effect of ternary SCMs to OPC ratio (0%, 10%, 20%, and 30%) on compressive strength and permeability of the green concrete were studied. The reaction products of the concrete containing OSP-LS-GGBFS SCM system were characterized by SEM and thermogravimetric analyses. The results obtained from this study revealed that the compressive strength of concrete mixed with ternary SCMs are improved compared with the reference specimens. The OSP-LS-GGBFS ternary SCMs-based mortars exhibited a lower porosity and permeability compared to the control specimens. However, when the substitution rate was 30%, the two parameters showed a decline. In addition, the samples incorporating ternary SCMs had a more refined pore structure and lower permeability than that of specimens adding OSP alone. This work expands the possibility of valorization of OSP for sustainable construction materials.

19.
Materials (Basel) ; 15(11)2022 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-35683148

RESUMEN

In order to control energy consumption and reduce pollution, the use of supplementary cementitious materials (SCMs) instead of cement to produce green cementitious materials can save energy, reduce emissions and achieve sustainable development. This study demonstrates the possibility of developing SCMs with iron tailings (IOTs), fly ash (FA) and ceramic powder (CP) ternary system, as well as the optimization and improvement scheme of gelation activation. The effects of activator dosage, mix ratio and substitution rate on mechanical properties of ternary SCMs system were investigated. The formation and evolution of hydration products were analyzed by differential thermogravimetric analysis (DTA) and scanning electron microscopy (SEM). The results of the study show that there is synergy in the system. The results show that there is synergy in the system and the hydration reaction is sufficient. At the substitution rate of 30%, the doping ratio of IOTs, CP and FA is 1:2:2 and the Ca(OH)2 is 0.6%, the strength reaches 39.9 MPa and the activity index is 91.5%, which can provide a basis for the application and more in-depth study of IOTs multi SCMs.

20.
RSC Adv ; 12(17): 10267-10279, 2022 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-35424976

RESUMEN

Removing salt from dye/salt mixtures using nanofiltration (NF) membranes needs to be improved to ensure high permeability, high selectivity, and antifouling performance. In this study, we used an interfacial polymerization (IP) technique to create a novel thin-film nanocomposite NF membrane by introducing two-dimensional MXene Ti3C2T x into the polyamide (PA) layer. Enhanced IP reaction rate facilitated the overflow of residual solvent from the fresh PA layer's edge due to the MXene-mediated IP strategy, resulting considerable bubble-like nodules on the membrane surface. The unique nanostructure of PA effective layer could be tuned by controlling the MXene concentration in aqueous phase solution, which finally promoted the obtained membranes with superb permselectivity. In this way, the water permeability was elevated to a maximum value of 45.12 L m-1 h-1, nearly 1.58-fold compared to the PA-pristine membrane. Moreover, the Ti3C2T x /NF membrane exhibited a superior dye/monovalent salt separation coefficient of 820, outperforming the pristine PA membrane and other NF membranes in the literature. Additionally, the MXene-assisted IP strategy designed an effective dye anti-fouling hydration layer, which played a crucial role in fouling resistance. This work illustrates a novel use of Ti3C2T x to successfully regulate high-performance TFN PA membranes for potential application in dye/salt separation.

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