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1.
Nature ; 578(7794): 240-245, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32051600

RESUMO

A quantum internet that connects remote quantum processors1,2 should enable a number of revolutionary applications such as distributed quantum computing. Its realization will rely on entanglement of remote quantum memories over long distances. Despite enormous progress3-12, at present the maximal physical separation achieved between two nodes is 1.3 kilometres10, and challenges for longer distances remain. Here we demonstrate entanglement of two atomic ensembles in one laboratory via photon transmission through city-scale optical fibres. The atomic ensembles function as quantum memories that store quantum states. We use cavity enhancement to efficiently create atom-photon entanglement13-15 and we use quantum frequency conversion16 to shift the atomic wavelength to telecommunications wavelengths. We realize entanglement over 22 kilometres of field-deployed fibres via two-photon interference17,18 and entanglement over 50 kilometres of coiled fibres via single-photon interference19. Our experiment could be extended to nodes physically separated by similar distances, which would thus form a functional segment of the atomic quantum network, paving the way towards establishing atomic entanglement over many nodes and over much longer distances.

2.
Bioorg Chem ; 143: 107047, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38154387

RESUMO

Chemical protein synthesis offers a powerful way to access otherwise-difficult-to-obtain proteins such as mirror-image proteins. Although a large number of proteins have been chemically synthesized to date, the acquisition to proteins containing hydrophobic peptide fragments has proven challenging. Here, we describe an approach that combines the removable backbone modification strategy and the peptide hydrazide-based native chemical ligation for the chemical synthesis of a 28 kDa full-length PET degrading enzyme IGGC (a higher depolymerization efficiency of variant leaf-branch compost cutinase (LCC)) containing hydrophobic peptide segments. The synthetic ICCG exhibits the enzymatic activity and will be useful in establishing the corresponding mirror-image version of ICCG.


Assuntos
Polietilenotereftalatos , Hidrolases/química , Fragmentos de Peptídeos , Peptídeos/química , Polietilenotereftalatos/química
3.
Environ Sci Technol ; 57(4): 1819-1827, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36652351

RESUMO

Surfactant-assisted interfacial polymerization (IP) has shown strong potential to improve the separation performance of thin film composite polyamide membranes. A common belief is that the enhanced performance is attributed to accelerated amine diffusion induced by the surfactant, which can promote the IP reaction. However, we show enhanced membrane performance for Tween 80 (a common surfactant), even though it decreased the amine diffusion. Indeed, the membrane performance is closely related to its polyamide roughness features with numerous nanovoids. Inspired by the nanofoaming theory that relates the roughness features to nanobubbles degassed during the IP reaction, we hypothesize that the surfactant can stabilize the generated nanobubbles to tailor the formation of nanovoids. Accordingly, we obtained enlarged nanovoids when the surfactant was added below its critical micelle concentration (CMC). In addition, both the membrane permeance and selectivity were enhanced, thanks to the enlarged nanovoids and reduced defects in the polyamide layer. Increasing the concentration above CMC resulted in shrunken nanovoids and deteriorated performance, which can be ascribed to the decreased stabilization effect caused by micelle formation. Interestingly, better antifouling performance was also observed for the surfactant-assisted membranes. Our current study provides mechanistic insights into the critical role of surfactant during the IP reaction, which may have important implications for more efficient membrane-based desalination and water reuse.


Assuntos
Nylons , Tensoativos , Osmose , Micelas , Membranas Artificiais
4.
Nanomedicine ; 47: 102618, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36270453

RESUMO

Ferroptosis plays an important role in ischemia-reperfusion (I/R)-induced cardiac injury and there are many defects in current targeted delivery of miRNAs for the treatment of ferroptosis. We herein report a unique hydrogel (Gel) that can be triggered by a near-infrared-II (NIR-II) light with deep tissue penetration and biocompatible maximum permissible exposure (MPE) value for in situ treatment after I/R. The mir-196c-3p mimic (mimics) and photothermal nanoparticles (BTN) were co-encapsulated in an injectable Gel (mimics + Gel/BTN) with NIR-II light-triggered release. Using 1064 nm light irradiation, local microenvironment photothermal-triggered on-demand noninvasive controllable delivery of miRNA was achieved, aiming to inhibit I/R-induced ferroptosis. Consequently, declined ferroptosis in cardiomyocytes and improved cardiac function, survival rate in rats was achieved through the controlled release of Gel/BTN mimics in I/R model to simultaneously inhibit ferroptosis hub genes NOX4, P53, and LOX expression.


Assuntos
Traumatismo por Reperfusão , Animais , Ratos
5.
Beijing Da Xue Xue Bao Yi Xue Ban ; 55(6): 1068-1073, 2023 Dec 18.
Artigo em Chinês | MEDLINE | ID: mdl-38101791

RESUMO

OBJECTIVE: To investigate the associated factors of endogenous erythropoietin (EPO) and its association with 10-year risks of atherosclerotic cardiovascular disease in a Chinese community-based general population. METHODS: The participants of this study were from an atherosclerosis cohort survey which was established by the Department of Cardiology, Peking University First Hospital in 2011. The cohort survey was performed in the Gucheng and Pingguoyuan communities of Shijingshan district in Beijing, China. The inclusion criteria of this study were: (1) endogenous EPO was measured; (2) health questionnaire data and other clinical data were complete; (3) participatants who had cardiovascular or cerebrovascular diseases (defined as self-reported coronary heart disease, stroke or transient ischemic attack) or anemia or estimated glomerular filtration rate (eGFR) < 60 mL/(min·1.73 m2) at baseline were excluded. Multivariate linear regression model was used to examine the associated factors of endogenous EPO. The participants were grouped into low (< 5%), moderate (5%-10%) and high risk (≥10%) groups, based on predicted 10-year cardiovascular disease risk using the prediction for atherosclerotic cardiovascular disease risk in China (China-PAR) equations. RESULTS: A total of 4 013 participants were included. Mean age of them was (55.9±8.2) years, 62.2% (n=2 496) of them were female, and 46.3% (n=1 859), 70.9% (n=2 845), 21.9% (n=879) had hypertension, dyslipidemia and diabetes, individually. The average body mass index was (26.1±3.3) kg/m2. The median of EPO level was 12.8 (9.3-17.4) IU/L and 25.1% (n=998) were at high 10-years risk of cardiovascular disease. Hemoglobin (ß=-0.05, 95%CI: -0.07 to -0.04) and eGFR ≥90 mL/(min·1.73 m2) (ß=-0.05, 95%CI: -0.07 to -0.04) were associated with lower in transformed EPO levels while hypertension (ß=0.08, 95%CI: 0.05 to 0.12) and obesity (ß=0.14, 95%CI: 0.09 to 0.18) were associated with higher in transformed EPO levels in multivariate linear regression analyses. Ten-year cardiovascular disease risks were positively associated with in transformed EPO levels (ß=0.07, 95%CI: 0.05 to 0.09). The participants at moderate and high cardiovascular disease risks had significant higher EPO levels than the low risk group (all P < 0.05). CONCLUSION: In community-based Beijing populations, endogenous EPO was associated with hemoglobin, renal function, obesity and hypertension. Individuals at high 10-years cardiovascular disease risks have higher endogenous EPO levels. Endogenous EPO may be a potential risk marker of cardiovascular disease.


Assuntos
Doenças Cardiovasculares , Eritropoetina , Hipertensão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Cardiovasculares/epidemiologia , Hemoglobinas , Hipertensão/epidemiologia , Obesidade , Fatores de Risco
6.
Phys Rev Lett ; 128(6): 060502, 2022 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-35213187

RESUMO

Hybrid matter-photon entanglement is the building block for quantum networks. It is very favorable if the entanglement can be prepared with a high probability. In this Letter, we report the deterministic creation of entanglement between an atomic ensemble and a single photon by harnessing the Rydberg blockade. We design a scheme that creates entanglement between a single photon's temporal modes and the Rydberg levels that host a collective excitation, using a process of cyclical retrieving and patching. The hybrid entanglement is tested via retrieving the atomic excitation as a second photon and performing correlation measurements, which suggest an entanglement fidelity of 87.8%. Our source of matter-photon entanglement will enable the entangling of remote quantum memories with much higher efficiency.

7.
Phys Rev Lett ; 126(9): 090501, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33750156

RESUMO

A cold atomic ensemble suits well for optical quantum memories, and its entanglement with a single photon forms the building block for quantum networks that give promise for many revolutionary applications. Efficiency and lifetime are among the most important figures of merit for a memory. In this Letter, we report the realization of entanglement between an atomic ensemble and a single photon with subsecond lifetime and high efficiency. We engineer dual control modes in a ring cavity to create entanglement and make use of three-dimensional optical lattice to prolong memory lifetime. The memory efficiency is 38% for 0.1 s storage. We verify the atom-photon entanglement after 1 s storage by testing the Bell inequality with a result of S=2.36±0.14.

8.
Phys Rev Lett ; 127(16): 160502, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34723577

RESUMO

In this Letter we report an experiment that verifies an atomic-ensemble quantum memory via a measurement-device-independent scheme. A single photon generated via Rydberg blockade in one atomic ensemble is stored in another atomic ensemble via electromagnetically induced transparency. After storage for a long duration, this photon is retrieved and interfered with a second photon to perform a joint Bell-state measurement (BSM). The quantum state for each photon is chosen based on a quantum random number generator, respectively, in each run. By evaluating correlations between the random states and BSM results, we certify that our memory is genuinely entanglement preserving.

9.
Environ Sci Technol ; 55(19): 13219-13230, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34314168

RESUMO

Forward osmosis (FO) hybrid systems have the potential to simultaneously recover nutrients and water from wastewater. However, the lack of membranes with high permeability and selectivity has limited the development and scale-up of these hybrid systems. In this study, we fabricated a novel thin-film nanocomposite membrane featuring an interlayer of Ti3C2Tx MXene intercalated with carbon nanotubes (M/C-TFNi). Owing to the enhanced confinement effect on interfacial degassing and increased amine monomer sorption by the interlayer, the resulting M/C-TFNi FO membrane has a greater degree of cross-linking and roughness. In comparison with the thin-film composite (TFC) membrane without an interlayered structure, the M/C-TFNi membrane attained a water flux that was four times higher and a lower specific salt flux. Notably, the M/C-TFNi membrane exhibited excellent concentration efficiency for real municipal wastewater and enhanced rejection of ammonia nitrogen, which breaks the permeability-selectivity upper bound. This study provides a new avenue for the rational design and development of high-performance FO membranes for environmental applications.


Assuntos
Nanotubos de Carbono , Purificação da Água , Membranas Artificiais , Osmose , Titânio , Águas Residuárias
10.
Environ Sci Technol ; 54(24): 15563-15583, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33213143

RESUMO

The separation properties of polyamide reverse osmosis and nanofiltration membranes, widely applied for desalination and water reuse, are constrained by the permeability-selectivity upper bound. Although thin-film nanocomposite (TFN) membranes incorporating nanomaterials exhibit enhanced water permeance, their rejection is only moderately improved or even impaired due to agglomeration of nanomaterials and formation of defects. A novel type of TFN membranes featuring an interlayer of nanomaterials (TFNi) has emerged in recent years. These novel TFNi membranes show extraordinary improvement in water flux (e.g., up to an order of magnitude enhancement) along with better selectivity. Such enhancements can be achieved by a wide selection of nanomaterials, ranging from nanoparticles, one-/two-dimensional materials, to interfacial coatings. The use of nanostructured interlayers not only improves the formation of polyamide rejection layers but also provides an optimized water transport path, which enables TFNi membranes to potentially overcome the longstanding trade-off between membrane permeability and selectivity. Furthermore, TFNi membranes can potentially enhance the removal of heavy metals and micropollutants, which is critical for many environmental applications. This review critically examines the recent developments of TFNi membranes and discusses the underlying mechanisms and design criteria. Their potential environmental applications are also highlighted.


Assuntos
Nanocompostos , Filtração , Membranas Artificiais , Nylons , Permeabilidade
11.
Phys Chem Chem Phys ; 22(39): 22627-22634, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33015694

RESUMO

NO electrochemical reduction (NOER) is a promising route for the removal of pollutant NO and the production of ammonia. In this work, by means of first-principles computations, we designed a series of single atom catalysts consisting of atomic transition metals anchored onto defective hexagonal boron nitride (h-BN) with boron vacancies (TM@h-BN). Among all nine candidates, our results revealed that Cu@h-BN and Ni@h-BN showed excellent NOER performances with relatively low limiting potentials of 0.23 and 0.31 V, respectively, which are comparable to (or even better than) that of the benchmark Pt catalyst (0.25 V). Moreover, Cu@h-BN and Ni@h-BN can significantly inhibit the competitive hydrogen evolution reaction, suggesting that the promoted ammonia formation is a low-potential and highly selective process.

12.
Neuroradiology ; 62(4): 439-445, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31853589

RESUMO

PURPOSE: Differential diagnosis between central neurocytoma and ependymoma is very important for making preoperative scheme. We explored the application of diffusion-weighted imaging (DWI) combined with apparent diffusion coefficient (ADC) in differential diagnosis between both. METHODS: The data of preoperative MR plain and contrast-enhanced scan, DWI and ADC values of neoplastic solid parts from 18 cases with central neurocytoma and 19 cases with lateral ventricular ependymoma, were retrospectively analyzed. Mann-Whitney test was used for the comparison of ADC values between central neurocytoma and ependymoma. The application of ADC values in the differential diagnosis between central neurocytoma and ependymoma was evaluated by ROC curve. RESULTS: The lesions showed hyperintensity-dominant mixed signal intensity on DWI and mean ADC was (0.65 ± 0.13) × 10-3 mm2/s in the 18 cases with central neurocytoma. In the 19 cases with ependymoma, 13 had hyperintensity-dominant mixed signal intensity on DWI and 6 had hypointensity-dominant mixed signal intensity on DWI, and mean ADC was (1.20 ± 0.23) × 10-3 mm2/s. The mean ADC value was significantly higher in the 19 cases with ependymoma than in the 18 cases with central neurocytoma (P < 0.001). The ADC of 0.87 × 10-3 mm2/s might be used as a threshold for differential diagnosis between central neurocytoma and ependymoma with an area under ROC curve of 0.98 ± 0.02 and a 95% confidence interval of 0.95-1.00. Its sensitivity, specificity, and accuracy were 90%, 100%, and 90%, respectively. CONCLUSION: There is a certain overlap in MRI imaging features between central neurocytoma and ependymoma. DWI combined with ADC value can improve peoperative diagnostic accuracy.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Ependimoma/diagnóstico por imagem , Neurocitoma/diagnóstico por imagem , Adolescente , Adulto , Criança , Meios de Contraste , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
13.
Phys Rev Lett ; 123(14): 140504, 2019 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-31702192

RESUMO

Entanglement between a single photon and a matter qubit is an indispensable resource for quantum repeater and quantum networks. With atomic ensembles, the entanglement creation probability is typically very low to inhibit high-order events. In this paper, we propose and experimentally realize a scheme that creates atom-photon entanglement with an intrinsic efficiency of 50%. We make use of Rydberg blockade to generate two collective excitations, lying in separate internal states. By introducing the momentum degree of freedom for the excitations, and interfering them via Raman coupling, we entangle the two excitations. Via retrieving one excitation, we create the entanglement between the polarization of a single photon and the momentum of the remaining atomic excitation, with a measured fidelity of 0.901(8). The retrieved optical field is verified to be genuine single photons. The realized entanglement may be employed to create entanglement between two distant nodes in a fully heralded way and with a much higher efficiency.

14.
J Pharmacol Exp Ther ; 365(3): 476-484, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29549156

RESUMO

A novel drug delivery system mediated by ultrasound (US) combined with microbubbles (MBs) (US+MB) could improve local drug concentration to enhance its efficacy. To investigate the influence of US+MB on methylprednisolone (MP), the effect of US+MB combined with MP (US+MB+MP) on lipopolysaccharide (LPS)-induced human mesangial cells (HMCs) and the underlying mechanism were explored in this study. The results revealed that HMCs treated with LPS underwent significant proliferation and exhibited an increase in nuclear transcription factor-κB (NF-κB) and transforming growth factor-ß1 (TGF-ß1) expression and a decrease in cellular apoptosis. This effect was significantly inhibited by MP (30-100 µg/ml), US combined with MBs (3.22 × 107 and 8.05 × 107 bubbles/ml), and US combined with both MBs (1.29 × 107 bubbles/ml) and MP (12 µg/ml) (US+MB1+MP12). The effect of US+MB1+MP12 was better than the effect of 12 µg/ml of MP alone and was similar to the effect of 100 µg/ml of MP. Additionally, the intracellular free MP content was significantly higher in the US+MB1+MP12 group than in the MP12 group. US combined with MBs not only inhibited LPS-induced HMC proliferation and NF-κB and TGF-ß1 expression and increased cellular apoptosis but also synergized with the pharmacologic effect of MP. The mechanism is partially due to the US-assisted MB local drug delivery and the anti-inflammatory effect induced by US combined with MBs.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Lipopolissacarídeos/farmacologia , Células Mesangiais/efeitos dos fármacos , Metilprednisolona/farmacologia , Microbolhas , Ondas Ultrassônicas , Apoptose/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Espaço Intracelular/metabolismo , Células Mesangiais/citologia , Células Mesangiais/metabolismo , Metilprednisolona/metabolismo , NF-kappa B/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
15.
Phys Rev Lett ; 121(8): 080501, 2018 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-30192608

RESUMO

Interference of multiple photons via a linear-optical network has profound applications for quantum foundation, quantum metrology, and quantum computation. Particularly, a boson sampling experiment with a moderate number of photons becomes intractable even for the most powerful classical computers. Scaling up from small-scale experiments requires highly indistinguishable single photons, which may be prohibited for many physical systems. Here we report a time-resolved multiphoton interference experiment by using photons not overlapping in their frequency spectra from three atomic-ensemble quantum memories. Time-resolved measurement enables us to observe nonclassical multiphoton correlation landscapes, which agree well with theoretical calculations. Symmetries in the landscapes are identified to reflect symmetries of the optical network. Our experiment can be further extended to realize boson sampling with many photons and plenty of modes, which thus may provide a route towards quantum supremacy with nonidentical photons.

16.
J Ultrasound Med ; 36(1): 189-199, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27925679

RESUMO

OBJECTIVES: This study aimed to compare the efficacy of shear wave elastography (SWE) and contrast-enhanced sonography in the differential diagnosis of superficial lymphadenopathy with abnormal imaging findings, which could not be otherwise confirmed by conventional sonography. METHODS: Forty-two enlarged superficial lymph nodes in 42 patients who met the screening criteria for this study were evaluated by both contrast-enhanced sonography and SWE. All lymph nodes underwent both methods using biopsy pathologic findings as a reference standard. RESULTS: The maximum elastic modulus, mean elastic modulus, and standard deviation of the elastic modulus were the main distinguishing features on SWE; they were significantly higher in malignant lesions than benign ones. The threshold value for the maximum elastic modulus was set at 37.9 kPa, and the sensitivity, specificity, and accuracy of differential diagnosis of superficial lymph nodes were 81.8%, 80.0%, and 81.0%, respectively. The diagnosis of benignity and malignancy by this index was statistically significant (P < .001). The lymph nodes were divided into benign and malignant groups according to different types based on the degree and range of intensity on contrast-enhanced sonography: intense or moderate homogeneous enhancement (n = 26) and heterogeneous, low homogeneous, or absent enhancement (n = 16). The sensitivity, specificity, and accuracy of contrast-enhanced sonography were 27.3%, 50.0%, and 38.1%. There was no statistically significant difference in the values between the benign and malignant groups (χ2 = 2.295; P = .130). CONCLUSIONS: Compared with contrast-enhanced sonography, SWE has better diagnostic value and efficiency in differentiation of superficial lymph nodes unexplained by conventional sonography. When conventional sonography cannot differentiate malignant superficial lymph nodes from benign ones, SWE is a useful adjunctive tool for assessment of lymph nodes.


Assuntos
Meios de Contraste , Aumento da Imagem/métodos , Linfonodos/diagnóstico por imagem , Linfadenopatia/diagnóstico por imagem , Ultrassonografia/métodos , Adulto , Diagnóstico Diferencial , Técnicas de Imagem por Elasticidade/métodos , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
18.
J Invasive Cardiol ; 36(5)2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38422533

RESUMO

A 60-year-old male presented to the emergency department of our hospital with persistent dull pain in the lower and middle sternum with generalized sweating after a heated argument with another person, and his symptoms did not resolve after 3 hours of onset.


Assuntos
Angiografia Coronária , Vasoespasmo Coronário , Eletrocardiografia , Humanos , Masculino , Pessoa de Meia-Idade , Vasoespasmo Coronário/diagnóstico , Vasoespasmo Coronário/fisiopatologia , Angiografia Coronária/métodos , Vasos Coronários/diagnóstico por imagem
19.
Sci Rep ; 14(1): 14114, 2024 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-38898142

RESUMO

The aim of this study was to develop a simple but effective nomogram to predict risk of septic cardiomyopathy (SCM) in the intensive care unit (ICU). We analyzed data from patients who were first admitted to the ICU for sepsis between 2008 and 2019 in the MIMIC-IV database, with no history of heart disease, and divided them into a training cohort and an internal validation cohort at a 7:3 ratio. SCM is defined as sepsis diagnosed in the absence of other cardiac diseases, with echocardiographic evidence of left (or right) ventricular systolic or diastolic dysfunction and a left ventricular ejection fraction (LVEF) of less than 50%. Variables were selected from the training cohort using the Least Absolute Shrinkage and Selection Operator (LASSO) regression to develop an early predictive model for septic cardiomyopathy. A nomogram was constructed using logistic regression analysis and its receiver operating characteristic (ROC) and calibration were evaluated in two cohorts. A total of 1562 patients participated in this study, with 1094 in the training cohort and 468 in the internal validation cohort. SCM occurred in 13.4% (147 individuals) in the training cohort, 16.0% (75 individuals) in the internal validation cohort. After adjusting for various confounding factors, we constructed a nomogram that includes SAPS II, Troponin T, CK-MB index, white blood cell count, and presence of atrial fibrillation. The area under the curve (AUC) for the training cohort was 0.804 (95% CI 0.764-0.844), and the Hosmer-Lemeshow test showed good calibration of the nomogram (P = 0.288). Our nomogram also exhibited good discriminative ability and calibration in the internal validation cohort. Our nomogram demonstrated good potential in identifying patients at increased risk of SCM in the ICU.


Assuntos
Cardiomiopatias , Unidades de Terapia Intensiva , Nomogramas , Sepse , Humanos , Masculino , Feminino , Cardiomiopatias/diagnóstico , Pessoa de Meia-Idade , Sepse/diagnóstico , Idoso , Curva ROC , Fatores de Risco , Medição de Risco/métodos
20.
J Contemp Brachytherapy ; 15(2): 123-129, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37215620

RESUMO

Purpose: To analyze the effects of different bladder and rectal volumes on the dose of organ at risks (OARs) and primary tumors following uniform preparation procedure. Material and methods: In this retrospective study, a total of 60 patients with cervical cancer treated with external beam radiation therapy (EBRT) combined with chemotherapy and brachytherapy (BT) during 2019-2022 were included (300 insertions). Then, tandem-ovoid applicators were placed and computed tomography (CT) scanning was performed after each insertion. Delineation of OARs and clinical target volumes (CTVs) were done according to GEC-ESTRO group recommendations. Finally, doses of high-risk clinical target volume (HR-CTV) and OARs were obtained from dose volume histogram (DVH) automatically generated by BT treatment planning system. Results: Following a uniform preparation procedure, the median bladder volume of 68.36 cc (range, 29.9-235.68 cc) was in optimal agreement with the recommended bladder volume of ≤ 70 ml, which avoided more manipulation and possible risk of adverse events during general anesthesia. As the bladder filling volume increased, there was no corresponding increase in rectal, HR-CTV, and small bowel volumes, while the sigmoid colon volume decreased. The median rectal volume was 54.95 cc (range, 24.92-168.1 cc), and as the rectal volume increased, HR-CTV, sigmoid colon, and rectum volumes increased, and conversely, small bowel volume decreased. HR-CTV changes with volume affected the rectum, bladder, and HR-CTV, but not the sigmoid colon and small intestine. Conclusions: Following a uniform preparation procedure, the bladder and rectum can also be controlled to an optimal volume (B ≤ 70 cc, R ≈ 40 cc), which is related to the dose of the bladder, rectum, and sigmoid colon.

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