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1.
Nature ; 604(7906): 457-462, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35444321

RESUMO

Gate-model quantum computers promise to solve currently intractable computational problems if they can be operated at scale with long coherence times and high-fidelity logic. Neutral-atom hyperfine qubits provide inherent scalability owing to their identical characteristics, long coherence times and ability to be trapped in dense, multidimensional arrays1. Combined with the strong entangling interactions provided by Rydberg states2-4, all the necessary characteristics for quantum computation are available. Here we demonstrate several quantum algorithms on a programmable gate-model neutral-atom quantum computer in an architecture based on individual addressing of single atoms with tightly focused optical beams scanned across a two-dimensional array of qubits. Preparation of entangled Greenberger-Horne-Zeilinger (GHZ) states5 with up to six qubits, quantum phase estimation for a chemistry problem6 and the quantum approximate optimization algorithm (QAOA)7 for the maximum cut (MaxCut) graph problem are demonstrated. These results highlight the emergent capability of neutral-atom qubit arrays for universal, programmable quantum computation, as well as preparation of non-classical states of use for quantum-enhanced sensing.

2.
Opt Express ; 32(12): 21345-21357, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38859490

RESUMO

In order to calculate the electromagnetic fields that are produced after light passes through a metasurface, simulation methods such as the Finite-Difference Time-Domain method are often employed. While these provide a good approximation to the fields, the level of detail at which the volume of space that the light is propagating in needs to be modelled and the time for which simulations need to run, mean that as the area of the metasurface is increased these simulations rapidly become unwieldy. In this paper we show how the result of a FDTD simulation of a unit cell can be used to generate a good approximation of the vectorial field that large area metasurfaces will generate, but using a fraction of the computational resources. This approach can provide an intermediate design step, allowing potentially interesting designs to be rapidly identified or discarded.

3.
Climacteric ; 27(1): 81-88, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38054425

RESUMO

In the USA it is estimated that more than one million women become menopausal each year. Coronary heart disease (CHD) is the leading cause of mortality in menopausal woman globally. The majority of perimenopausal to postmenopausal women experience bothersome symptoms including hot flashes, night sweats, mood liability, sleep disturbances, irregular bleeding and sexual dysfunction. While menopausal hormone therapy (HT) effectively treats most of these symptoms, use of HT has become confusing, especially related to CHD risk. Despite years of observational and retrospective studies supporting a CHD benefit and improved survival among HT users, the Heart and Estrogen/Progestin Replacement Study (HERS) and the Women's Health Initiative (WHI) raised doubts about this long-held premise. The timing hypothesis has since emerged and states that when HT is initiated in younger women, soon after menopause onset, there may be cardiovascular benefit. The following review discusses the roller-coaster history of HT use as it pertains to CHD in postmenopausal women. Studies that highlight HT's CHD benefit are reviewed and provide reassurance that HT utilized in appropriately selected younger postmenopausal women close to the onset of menopause is safe from a cardiovascular perspective, in line with consensus recommendations.


Assuntos
Doença das Coronárias , Menopausa , Humanos , Feminino , Estudos Retrospectivos , Terapia de Reposição Hormonal , Terapia de Reposição de Estrogênios/efeitos adversos , Saúde da Mulher , Estudos Observacionais como Assunto
4.
J Endocrinol Invest ; 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38536656

RESUMO

PURPOSE: Primary aldosteronism (PA) diagnosis is affected by antihypertensive drugs that are commonly taken by patients with suspected PA. In this study, we developed and validated a diagnostic model for screening PA without drug washout. METHODS: We retrospectively analyzed 1095 patients diagnosed with PA or essential hypertension. Patients were randomly grouped into training and validation sets at a 7:3 ratio. Baseline characteristics, plasma aldosterone concentration (PAC), and direct renin concentration (DRC) before and after drug washout were separately recorded, and the aldosterone-to-renin ratio (ARR) was calculated. RESULTS: PAC and ARR were higher and direct renin concentration was lower in patients with PA than in patients with essential hypertension. Furthermore, the differences in blood potassium and sodium concentrations and hypertension grades between the two groups were significant. Using the abbreviations potassium (P), ARR (A), PAC (P), sodium (S), and hypertension grade 3 (3), the model was named PAPS3. The PAPS3 model had a maximum score of 10, with the cutoff value assigned as 5.5; it showed high sensitivity and specificity for screening PA in patients who exhibit difficulty in tolerating drug washout. CONCLUSION: PA screening remains crucial, and standard guidelines should be followed for patients to tolerate washout. The PAPS3 model offers an alternative to minimize risks and enhance diagnostic efficiency in PA for those facing washout challenges. Despite its high accuracy, further validation of this model is warranted through large-scale clinical studies.

5.
Br Poult Sci ; : 1-8, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38995225

RESUMO

1. This trial investigated the effect on embryo injected with ochratoxin A (OTA) and the growth performance, jejunal morphology and barrier of ducklings to 21 d old.2. Two hundred forty, fertilised eggs were individually weighed and randomly assigned to two groups, a control (CON) and the OTA treatment, according to average egg weight. On d 13 of embryonic development, the treatment group was injected with 8 ng OTA/g egg and the CON group was injected with NaHCO3 solution as a placebo. All newly hatched ducklings were assigned to the CON or OTA group based on the different treatments. Each treatment consisted of six replicates and each included 10 ducklings and the experiment lasted until 21 d of age.3. The results showed that embryos injected with OTA affected the 21 d body weight (BW) and average daily gain (ADG) of ducklings (p < 0.05). OTA exposure increased the relative weights of the liver, pancreas, gizzard, proventriculus and jejunum (p < 0.05); and decreased the relative length of the jejunum of ducklings (p < 0.05). Moreover, jejunal crypt depth increased (p < 0.05) and the villus height-to-crypt depth ratio (Vh/Cd) decreased in the OTA-injected group (p < 0.05). Compared with those in the CON group, the mRNA expression of Zonula Occludens-1; (ZO-1) (p = 0.0582) and Occludin; (p = 0.0687) in the OTA treatment group was downregulated.4. The findings demonstrated that a single low-dose injection of OTA increased body weight and daily gain in ducklings. Moreover, embryo exposure to OTA had negative effects with increased relative weight of organs and the jejunal crypt depth, decreased relative length of the intestine and mRNA expression of tight junctions (ZO-1, Occludin).

6.
Br Poult Sci ; : 1-7, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38717938

RESUMO

1. Non-coding RNAs, such as miRNAs, play a crucial role in chicken feather growth rate. However, circular RNA (circRNA) expression profiles in fast- and slow-feathering chickens that follow and do not follow Mendelian inheritance are unclear.2. The circRNA expression profiles was analysed by RNA sequencing of hair follicles of slow-feathering chickens that follow genetic rules and fast-feathering chickens that did not follow genetic rules. Differentially expressed circRNA-miRNA-mRNA competing endogenous RNA (ceRNA) network was then constructed and the key factors and regulation mechanisms controlling feather growth rate were identified.3. The results revealed that 67 circRNAs were significantly differentially expressed in hens, including 22 up-regulated and 45 down-regulated circRNAs in non-Mendelian inheritance-mediated fast-feathering hens compared with Mendelian inheritance-mediated slow-feathering hens. In addition, 16 significantly differentially expressed circRNAs were identified in cockerels, including nine up-regulated and seven down-regulated circRNAs in non-Mendelian inheritance-mediated fast- compared with Mendelian inheritance-mediated slow-feathering cocks. Moreover, circRNA-mediated ceRNA regulation of hair follicle formation was particularly abundant in the Jak-STAT, Wnt and Toll-like receptor signalling pathways. Furthermore, circABI3BP was seen to be a crucial circRNA in regulating feather growth rate, by binding with gga-miR-1649-5p to regulate SSTR2 expression.4. In conclusion, this study analysed circRNA expression profiles in fast- and slow-feathering chickens that follow and do not follow Mendelian inheritance, which laid the foundation for understanding the role of circRNA in chicken feather growth rate.

7.
Zhonghua Nei Ke Za Zhi ; 63(5): 517-520, 2024 May 01.
Artigo em Zh | MEDLINE | ID: mdl-38715493

RESUMO

A 52-year-old woman was admitted with a primary complaint of abdominal distension and increased abdominal circumference for more than half a year. There was no evidence of infection or solid tumor on abdominocentesis or laparoscopic surgery. Concurrently, smoldering multiple myeloma was diagnosed. Due to refractory ascites and portal hypertension, a transjugular intrahepatic portosystemic shunt was performed, but the efficacy was not satisfactory. As the anemia progressed, she was finally diagnosed with active multiple myeloma after monoclonal plasma cells were detected in the ascites by flow cytometry. Treated with a triplet regimen that included bortezomib, cyclophosphamide, and dexamethasone (BCD), she achieved a very good partial response and ascites regressed.


Assuntos
Ascite , Mieloma Múltiplo , Humanos , Feminino , Pessoa de Meia-Idade , Ascite/etiologia , Mieloma Múltiplo/complicações , Dexametasona/uso terapêutico , Dexametasona/administração & dosagem , Ciclofosfamida/uso terapêutico , Bortezomib/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Hipertensão Portal
8.
Zhonghua Yi Xue Za Zhi ; 104(3): 180-185, 2024 Jan 16.
Artigo em Zh | MEDLINE | ID: mdl-38220442

RESUMO

Objective: To investigate the efficacy and safety of bupivacaine liposome for pericapsular nerve group block (PENGB) for postoperative analgesia in elderly patients with total hip replacement. Methods: A total of 42 elderly patients underwent total hip replacement were selected in the Second Affiliated Hospital of Wenzhou Medical University from May to July in 2023, including 19 males and 23 females, aged (68.8±6.3) years, the American Society of Anesthesiologists (ASA) grade Ⅰ to Ⅲ. They were divided into bupivacaine liposome group (observation group) and levobupivacaine hydrochloride group (control group) according to random number table, with 21 cases in each group. All the patients were anesthetized by lumbar anesthesia combined with PENGB. During PENGB, the observation group was injected with 10 ml (133 mg) bupivacaine liposome+5 ml normal saline, and the control group was injected with 10 ml (75 mg) levobupivacaine hydrochloride+5 ml normal saline. The primary outcome measures included the rest and movement visual analogue scale (VAS) scores at 6, 12, 24, 36, 48, 60, and 72 h after operation, the sufentanil consumption in analgesic pump, the numbers of analgesic pump compressions, and the rates of additional parexib sodium use in ward. The secondary outcome measures were the changes in lower limb muscle strength, the length of hospital stay and the occurrence of adverse reactions. Results: There was no significant difference in the rest and movement VAS scores between the two groups at pre-operation and at 6 h after operation (P>0.05);but the rest and movement VAS scores at 12, 24, 36, 48, 60 and 72 h after operation in observation group were significantly lower than those in control group (P<0.05); the rest and movement VAS scores at 6, 12, 24, 36, 48, 60 and 72 h after operation were lower than those at pre-operation in two group (P<0.05). The consumption of sufentanil in analgesic pump and parexib sodium usage in observation group were lower than those in control group at 12, 24, 36 and 48 h after operation (P<0.05). The total number of analgesic pump compressions, the number of effective compressions and the number of ineffective compressions in 48 h in observation group were lower than those in control group (P<0.05). The muscle strength of the lower limbs of all patients were able to move against gravity at 12 h after operation. The incidence of nausea in 48 h after operation in observation group was 9.5% (2/21), which was lower than 42.9% (9/21) in control group (P=0.014). No postoperative vomiting occurred in all patients. The length of the hospital stay was (9.3±2.2) d in observation group and (8.9±1.9) d in control group, and there was no significant difference between the two groups (P=0.500). Conclusion: Compared with levobupivacaine hydrochloride, liposomal bupivacaine in PENGB provides analgesic effects for up to 72 h after total hip replacement in elderly patients, reduces postoperative opioid and other analgesics usage, decreases the incidence of postoperative nausea, and has a minor effect on lower limb movement without prolonging hospitalization.


Assuntos
Analgesia , Artroplastia de Quadril , Masculino , Idoso , Feminino , Humanos , Levobupivacaína , Lipossomos , Sufentanil/efeitos adversos , Anestésicos Locais , Nervo Femoral , Solução Salina , Dor Pós-Operatória , Bupivacaína , Analgésicos Opioides , Analgésicos , Náusea e Vômito Pós-Operatórios , Sódio
9.
Zhonghua Jie He He Hu Xi Za Zhi ; 47(2): 183-189, 2024 Feb 12.
Artigo em Zh | MEDLINE | ID: mdl-38309972

RESUMO

Platelets are important cells in hemostatic and coagulative reactions. Interestingly, platelets-related immunopathological mechanism and clinical research have become one of the hot research topics in tuberculosis at home and abroad in recent years. Platelets get involved in host chronic inflammation and pulmonary immune response, thus playing a negative regulatory role in tuberculosis. This is achieved through direct internalization of Mycobacterium tuberculosis and indirect interaction with immune cells. In addition, patients with tuberculosis often have thrombocytosis, and there is increasing evidence that anti-platelet therapy as a host-directed therapy has demonstrable clinical benefit in tuberculosis control. Platelet inhibition may be an emerging therapeutic strategy for tuberculosis. This review aims to highlight the research progress in platelets and tuberculosis.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Tuberculose/tratamento farmacológico , Plaquetas , Pulmão
10.
Zhonghua Wai Ke Za Zhi ; 62(5): 400-405, 2024 May 01.
Artigo em Zh | MEDLINE | ID: mdl-38548608

RESUMO

Objective: To examine the clinical outcomes of patients undergoing total thoracoscopic aortic-mitral double-valve replacement. Methods: This is a retrospective case series study. The clinical data of 50 patients who underwent double-valve replacement under a total thoracoscopic two-port approach from November 2021 to August 2022 in the Department of Cardiovascular Surgery, Fujian Medical University Union Hospital were retrospectively analyzed. There were 32 males and 18 females, with an age of (55.3±8.8) years (range: 21 to 62 years). Among them, 36 cases had rheumatic heart disease and 14 cases had infective endocarditis. The 3rd intercostal space between the right anterior axillary line and the midclavicular line was selected as the main operating hole, the total thoracoscopic double-valve replacement were successfully carried out. Baseline data, intraoperative information, surgical outcomes, and postoperative complications were collected for all patients. Results: The cardiopulmonary bypass time was (168.2±30.9) minutes (range: 125 to 187 minutes), the aortic cross-clamping time was (118.8±16.5) minutes (range: 96 to 147 minutes). Five patients received bioprosthetic valves, and 45 received mechanical prosthetic valves. Postoperative mechanical ventilation lasted (9.6±3.4) hours (range: 5.1 to 14.2 hours), the ICU stay was (24.8±7.3) hours (range: 16.3 to 30.1 hours), and the postoperative hospital stay was (6.5±1.2) days (range: 5.0 to 8.0 days). Four patients received red blood cell transfusions of (2.7±0.9) units (range: 2 to 4 units), and the postoperative chest drainage volume was (222.1±56.3) ml (range: 175 to 289 ml). No deaths occurred intraoperatively or in the early postoperative period. One patient required reoperation due to bleeding in the aortic incision. Three patients had mild to moderate paravalvular leakage around the prosthetic aortic valve, with no cases of third-degree atrioventricular block or conversions to median sternotomy. Conclusions: The early outcomes of total thoracoscopic double valve replacement surgery are satisfactory, demonstrating safety and efficacy. This surgical approach expands the scope of total thoracoscopic cardiac surgery, which warrants further investigation and research.


Assuntos
Valva Aórtica , Implante de Prótese de Valva Cardíaca , Toracoscopia , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto , Implante de Prótese de Valva Cardíaca/métodos , Toracoscopia/métodos , Valva Aórtica/cirurgia , Resultado do Tratamento , Valva Mitral/cirurgia , Adulto Jovem , Complicações Pós-Operatórias , Cardiopatia Reumática/cirurgia
11.
Zhonghua Wai Ke Za Zhi ; 62(5): 438-442, 2024 May 01.
Artigo em Zh | MEDLINE | ID: mdl-38548614

RESUMO

Objective: To evaluate the clinical outcomes of thoracic endovascular aortic repair (TEVAR) in the treatment of Stanford type B aortic dissection (TBAD) in Marfan syndrome patients who had no history of aortic arch replacement. Methods: This is a retrospective case-series study. From January 2009 to December 2019,the clinical data of Marfan syndrome patients who underwent TEVAR for TBAD at the Department of Vascular Surgery were collected. A total of 23 patients were enrolled,including 15 males and 8 females. The age was (38.0±11.0) years (range:24 to 56 years). Among them,12 patients had history of ascending aortic surgery. Details of TEVAR,perioperative complications and reintervention were recorded and survival rate was analyzed by Kaplan-Meier curve. Results: Technical success was 91.3% (21/23). Two patients with technical failure were as follows:one patient had type Ⅰa endoleak at the completion angiography,which healed spontaneously during the follow-up,and the other patient suffered aortic intimal intussusception after the deployment of the first stent-graft, and the second stent-graft was deployed. However, type Ⅲ endoleak was detected,which disappeared during the follow-up. One patient died during hospitalization. The median follow-up time (M(IQR)) was 60 (48) months (range:12 to 132 months). Reintervention was performed on 7 patients,including 3 distal stent-graft-induced new entry,2 distal aortic dilation,1 Ⅰa endoleak and 1 retrograde type A aortic dissection,respectively. Five-year cumulative survival rate was 86.7% (95%CI:86.6% to 86.8%) and the 5-year freedom from reintervention rate was 81.8% (95%CI:61.8% to 92.8%). Conclusions: TEVAR is feasible in the treatment of TBAD in Marfan syndrome patients who has no history of aortic arch replacement. It has high technical success rate and low perioperative complication.


Assuntos
Dissecção Aórtica , Implante de Prótese Vascular , Procedimentos Endovasculares , Síndrome de Marfan , Stents , Humanos , Masculino , Feminino , Adulto , Dissecção Aórtica/cirurgia , Síndrome de Marfan/complicações , Pessoa de Meia-Idade , Estudos Retrospectivos , Procedimentos Endovasculares/métodos , Implante de Prótese Vascular/métodos , Resultado do Tratamento , Aneurisma da Aorta Torácica/cirurgia , Adulto Jovem , Aorta Torácica/cirurgia , Complicações Pós-Operatórias/etiologia
12.
Zhonghua Yan Ke Za Zhi ; 60(2): 147-155, 2024 Feb 11.
Artigo em Zh | MEDLINE | ID: mdl-38296320

RESUMO

Objective: This study aimed to observe the clinical efficacy of precise suturing of posterior elastic layer fissures guided by intraoperative optical coherence tomography (OCT) in conjunction with anterior chamber puncture and drainage, and corneal thermokeratoplasty for the treatment of severe acute edematous keratoconus. Methods: Non-randomized controlled trial. Data were collected for a study involving 31 cases of acute edematous keratoconus patients who underwent surgical treatment at the Shandong Eye Hospital between June 2017 and July 2021. Among them, there were 30 male and 1 female patients, with an age range of 11 to 32 years and a mean age of (19.80±5.80) years. Eighteen patients in the study group underwent precise suturing of posterior elastic layer fissures guided by intraoperative OCT, in combination with anterior chamber puncture and drainage, and corneal thermokeratoplasty. Thirteen patients in the control group did not undergo suturing. Preoperative visual acuity, corneal edema diameter, corneal thickness, and posterior elastic layer fissure length were collected. Evaluation was performed using slit lamp microscopy, anterior segment OCT, and other methods to assess the time of initial postoperative corneal edema resolution and closure of the posterior elastic layer fissure. Deep lamellar keratoplasty was performed 2 to 4 weeks after edema resolution, and the corneal bed scar repair and visual acuity of the two groups were compared. Results: In the suturing group, the corneas of all 18 patients were accurately sutured to the deep stromal layer near the posterior elastic layer. The time for corneal edema resolution was 2.50 (1.00, 6.25) days in the suturing group and 7.00 (6.00, 10.50) days in the control group. The fissure healing time was 7.50 (7.00, 12.00) days in the suturing group and 14.00 (9.00, 14.00) days in the control group. The differences were statistically significant (all P<0.05). After 2 weeks, the central corneal thickness decreased to (529.80±174.50) µm in the suturing group and (612.00±205.12) µm in the control group. The suturing group showed accurate corneal suturing to the deep stromal layer near the posterior elastic layer, resulting in central corneal flattening, closure of voids in the stroma, and a significant decrease in corneal thickness. All 18 patients in the suturing group successfully completed deep lamellar keratoplasty, with 6 cases (6/18) experiencing mild graft bed leakage during surgery but without affecting the deep lamellar keratoplasty. One year postoperatively, the visual acuity (logarithm of the minimum resolution angle) was 0.23±0.12 in the suturing group and 0.33±0.11 in the control group, with a statistically significant difference (P<0.05). Conclusions: In the treatment of severe acute edematous keratoconus, precise suturing of posterior elastic layer fissures guided by intraoperative OCT, in conjunction with anterior chamber puncture and drainage, and corneal thermokeratoplasty, can rapidly alleviate corneal edema and promote the healing of posterior elastic layer fissures. This approach achieves better visual outcomes for subsequent lamellar keratoplasty surgeries. The use of intraoperative OCT guidance allows accurate positioning of the posterior elastic layer fissure in terms of location, direction, and depth of corneal stromal voids, thereby assisting surgeons in precise suturing.


Assuntos
Edema da Córnea , Transplante de Córnea , Ceratocone , Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Criança , Ceratocone/cirurgia , Tomografia de Coerência Óptica/métodos , Edema da Córnea/cirurgia , Córnea/cirurgia , Suturas
13.
Osteoarthritis Cartilage ; 31(6): 819-828, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36889626

RESUMO

OBJECTIVE: We primarily aimed to investigate whether there are phenotypic and genetic links underlying body mass index (BMI) and overall osteoarthritis (OA). We then intended to explore whether the relationships differ across sexes and sites. METHOD: We first evaluated the phenotypic association between BMI and overall OA using data from the UK Biobank. We then investigated the genetic relationship leveraging summary statistics of the hitherto largest genome-wide association studies performed for BMI and overall OA. Finally, we repeated all analyses in a sex- (female, male) and site- (knee, hip, spine) specific manner. RESULTS: Observational analysis suggested an increased hazard of diagnosed OA per 5 kg/m2 increment in BMI (hazard ratio = 1.38, 95% confidence interval (CI) = 1.37-1.39). A positive overall genetic correlation was observed for BMI and OA (rg = 0.43, P = 4.72 × 10-133), corroborated by 11 significant local signals. Cross-trait meta-analysis identified 34 pleiotropic loci shared between BMI and OA, of which seven were novel. Transcriptome-wide association study revealed 29 shared gene-tissue pairs, targeting nervous, digestive, and exo/endocrine systems. Mendelian randomization demonstrated a robust BMI-OA causal relationship (odds ratio = 1.47, 95% CI = 1.42-1.52). A similar pattern of effects was observed in sex- and site-specific analyses, with BMI affecting OA comparably in both sexes and most strongly in the knee. CONCLUSION: Our work demonstrates an intrinsic relationship underlying BMI and overall OA, reflected by a pronounced phenotypic association, significant biological pleiotropy, and a putative causal link. Stratified analysis further reveals that the effects are distinct across sites and comparable across sexes.


Assuntos
Osteoartrite do Joelho , Masculino , Feminino , Humanos , Índice de Massa Corporal , Osteoartrite do Joelho/epidemiologia , Osteoartrite do Joelho/genética , Estudo de Associação Genômica Ampla , Causalidade , Articulação do Joelho , Polimorfismo de Nucleotídeo Único
14.
Opt Lett ; 48(12): 3255-3258, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37319075

RESUMO

Broadband supercontinuum (SC) light sources generated through nonlinear effects in solid-core photonic crystal fibers (PCFs) have been widely used in spectroscopy, metrology, and microscopy, leading to great application successes. The short-wavelength extension of such SC sources, a longstanding challenge, has been the subject of intensive study over the past two decades. However, the exact mechanism of blue and ultraviolet light generation, especially for some resonance spectral peaks in the short-wavelength regime, is not yet fully understood. Here, we demonstrate that the effect of inter-modal dispersive-wave radiation, which results from phase matching between pump pulses at the fundamental optical mode and packets of linear waves at some higher-order modes (HOMs) propagating in the PCF core, might be one of the critical mechanisms that can result in some resonance spectral components with wavelengths much shorter than that of the pump light. We observed in an experiment that several spectral peaks resided in the blue and ultraviolet regimes of the SC spectrum, whose central wavelengths can be tuned by varying the PCF-core diameter. These experimental results can be interpreted well using the inter-modal phase-matching theory, providing some useful insights into the SC generation process.


Assuntos
Tecnologia de Fibra Óptica , Raios Ultravioleta , Fótons , Microscopia
15.
Phys Rev Lett ; 130(9): 092701, 2023 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-36930937

RESUMO

The ^{18}O(α,γ)^{22}Ne reaction is critical for AGB star nucleosynthesis due to its connection to the abundances of several key isotopes, such as ^{21}Ne and ^{22}Ne. However, the ambiguous resonance energy and spin-parity of the dominant 470 keV resonance leads to substantial uncertainty in the ^{18}O(α,γ)^{22}Ne reaction rate for the temperature of interest. We have measured the resonance energies and strengths of the low-energy resonances in ^{18}O(α,γ)^{22}Ne at the Jinping Underground Nuclear Astrophysics experimental facility (JUNA) with improved precision. The key 470 keV resonance energy has been measured to be E_{α}=474.0±1.1 keV, with such high precision achieved for the first time. The spin-parity of this resonance state is determined to be 1^{-}, removing discrepancies in the resonance strengths in earlier studies. The results significantly improve the precision of the ^{18}O(α,γ)^{22}Ne reaction rates by up to about 10 times compared with the previous data at typical AGB temperatures of 0.1-0.3 GK. We demonstrate that such improvement leads to precise ^{21}Ne abundance predictions, with an impact on probing the origin of meteoritic stardust SiC grains from AGB stars.

16.
Phys Chem Chem Phys ; 25(37): 25573-25580, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37721039

RESUMO

PrBi, a sister member of the rare-earth monopnictide family, is an excellent candidate for studying extreme magnetoresistance and nontrivial topological electronic states. In this study, we perform angular magnetoresistance measurements as well as bulk and surface band structure calculations on this compound. PrBi's magnetoresistance is revealed to be significantly angle-dependent and shows a fourfold symmetry as always observed in the nonmagnetic isostructural counterparts, including LaSb, LaBi, and LuBi. Its angular magnetoresistance can be reproduced well using the semiclassical two-band model. The deduced parameters suggest that PrBi hosts an elongated electron pocket with a mobility anisotropy of ∼3.13 and is slightly uncompensated in its carrier concentration. Our bulk and surface band structure calculations confirm the anisotropic electronic features. Moreover, we reveal that a nodal-line-shaped surface state appears at the X̄ point, and is associated with the quadratic dispersion along the -X̄ direction, and the linear type-I Dirac dispersion along the X̄-M̄ direction. Owing to the type-I Dirac dispersion feature, PrBi could serve as a promising material platform for studying many unexpected physical properties, such as the highly anisotropic transport and valley polarization of electrons.

17.
Clin Radiol ; 78(4): e328-e335, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36746725

RESUMO

AIM: To develop a unified deep-learning-based method for automated intracerebral haemorrhage (ICH) segmentation on computed tomography (CT) images with different layer thickness parameters. MATERIALS AND METHODS: A total of 134 patients from an internal database (67 patients) and an external database (called CQ500, 67 patients) were employed. The CT examinations included multiple layer thicknesses such as 0.625, 1.25 and 5 mm. ICH segmentation was performed by a coarse-to-fine strategy, including three stages of three-dimensional (3D) skull-stripping segmentation, 3D ICH localisation segmentation, and two-dimensional (2D) ICH fine segmentation. The three stages shared the same sICHNet for segmentation and employed mixed precision training to speed up the training process. In addition, the 3D contextual information from CT was maintained by formatting the consecutive slices into a three-channel image in the 2D ICH fine segmentation. RESULTS: Experimental results demonstrated that the coarse-to-fine segmentation strategy achieved the best performance with a mean Dice coefficient of 0.887. ICH volume consistency was observed (p<0.05) between manual and automatic segmentations, and between segmentations of same individual but with different layer thicknesses in internal dataset and external database. Automated segmentation achieved a relatively consistent segmentation time of 20.01 ± 2.03 seconds no matter the layer thickness of the CT images and the extent of ICH. Longitudinal studies with conservative management and surgical treatment were also visualised. CONCLUSIONS: The coarse-to-fine deep learning strategy achieved the best ICH segmentation performance on CT images. The automated segmentation was 5-42 times faster than manual segmentation given ICH of different extents and using different layer thickness parameters.


Assuntos
Aprendizado Profundo , Humanos , Tomografia Computadorizada por Raios X/métodos , Hemorragia Cerebral/diagnóstico por imagem , Cabeça , Processamento de Imagem Assistida por Computador/métodos
18.
Clin Radiol ; 78(5): 375-380, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36805286

RESUMO

AIM: To investigate whether spleen imaging characteristics of baseline 2-[18F]-fluoro-2-deoxy-d-glucose (18F-FDG) positron-emission tomography (PET)/computed tomography (CT) can help to predict the clinical outcome in complete response (CR) diffuse large B-cell lymphoma (DLBCL). MATERIALS AND METHODS: Three hundred and six patients with DLBCL were enrolled in the study and divided into recurrence and non-recurrence groups. The splenic abnormalities were compared using the chi-square test and quantitative indexes were compared using the t-test. The Cox proportional hazard regression model was used for univariate and multivariate analysis. Kaplan-Meier curves and log-rank tests were used to compare progression-free survival (PFS). Propensity score matching (PSM) was used to match patients with and without splenic abnormalities according to age, gender, and initial Ann Arbor stage at a 1:2 ratio (52:104); then the recurrence and PFS results were compared again. RESULTS: Age, international prognostic index (IPI), stage, splenomegaly, and focal splenic lesions were significantly different between the recurrence and non-recurrence groups. IPI, stage, baseline spleen mean standard uptake value (SUVmean)/liver SUVmean, splenomegaly, and focal lesions were selected by Cox single-factor analysis, and only focal lesions showed a statistical difference in terms of Cox multivariate analysis (p=0.022, hazard ratio [HR]: 2.843). After PSM, focal splenic lesions (n=20) were still statistically different (p=0.003) between the recurrence and non-recurrence groups, and this played an essential role in PFS forecasting (p=0.0004, HR: 3.767). CONCLUSION: Focal splenic lesions were identified as an independent risk factor for the prognosis of DLBCL. Pretreatment splenomegaly and focal splenic lesions appeared to be related to the relapse and PFS of DLBCL patients. Focal splenic lesions still showed meaningful predictive value even with propensity matching.


Assuntos
Linfoma Difuso de Grandes Células B , Esplenopatias , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Fluordesoxiglucose F18 , Prognóstico , Esplenomegalia , Estudos Retrospectivos , Recidiva Local de Neoplasia , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Tomografia por Emissão de Pósitrons
19.
Clin Radiol ; 78(1): 8-17, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36192203

RESUMO

AIM: To establish and verify a 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)/computed tomography (CT)-based radiomics nomogram to predict mediastinal lymph node metastasis (LNM) in non-small cell lung cancer (NSCLC) patients preoperatively. MATERIALS AND METHODS: This retrospective study enrolled 155 NSCLC patients (primary cohort, n=93; validation cohort, n=62). For each patient, 2,704 radiomic features were extracted from the primary lung cancer regions. Four procedures including the Mann-Whitney U-test, Spearman's correlation analysis, minimum redundancy-maximum relevance (mRMR), and least absolute shrinkage and selection operator (LASSO) binary logistic regression were utilised for determining essential features and establishing a radiomics signature. After that, a nomogram was established. The nomogram's potential was assessed based on its discrimination, calibration, and clinical usefulness. The radiomics signature and nomogram predictive performances were evaluated with respect to the area under the receiver operating characteristic curve (AUC), specificity, accuracy, and sensitivity. RESULTS: The radiomics signature composed of eight selected features had good discriminatory performance of LNM versus non-LNM groups an AUC of 0.851 and 0.826 in primary and validation cohorts, respectively. The nomogram also indicated good discrimination with an AUC of 0.869 and 0.847 in the primary and validation cohorts, respectively. Furthermore, good calibration was demonstrated utilising the nomogram. CONCLUSIONS: An 18F-FDG PET/CT-based radiomics nomogram that integrates the radiomics signature and age was promoted to predict mediastinal LNM within NSCLC patients, which could potentially facilitate individualised therapy for mediastinal LNM before treatment. The nomogram was beneficial in clinical practice, as illustrated by decision curve analysis.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Metástase Linfática/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Fluordesoxiglucose F18 , Estudos Retrospectivos , Neoplasias Pulmonares/diagnóstico por imagem , Nomogramas
20.
J Chem Phys ; 158(20)2023 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-37226996

RESUMO

The morphology of dodecane in a nanopore at temperatures typical in exploited or depleted oil reservoirs is investigated using molecular dynamics simulation. The dodecane morphology is found to be determined by interactions between interfacial crystallization and surface wetting of the simplified oil, while "evaporation" only plays a minor role. The morphology changes from an isolated, solidified dodecane droplet to a film with orderly lamellae structures remaining within, and finally to a film containing randomly distributed dodecane molecules, as the system temperature increases. In a nanoslit under the impact of water, since water wins against oil in surface wetting on the silica surface due to electrostatic interaction induced hydrogen bonding between water and the silanol group of silica, the spreading of dodecane molecules over the silica surface is impeded by this water confinement mechanism. Meanwhile, interfacial crystallization is enhanced, leading to always an isolated dodecane "droplet," with crystallization weakening as the temperature increases. Since dodecane is immiscible to water, there is no mechanism for dodecane to escape the silica surface, and the competition of surface wetting between water and oil determines the morphology of the crystallized dodecane droplet. For the CO2-dodecane system in a nanoslit, CO2 is an efficient solvent for dodecane at all temperatures. Therefore, interfacial crystallization rapidly disappears. The competition of surface adsorption between CO2 and dodecane is secondary for all cases. The dissolution mechanism is a clear clue for the fact that CO2 is more effective than water flooding in oil recovery for a depleted oil reservoir.

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