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1.
Phys Rev Lett ; 132(4): 045001, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38335335

RESUMO

Laser wakefield acceleration is paving the way for the next generation of electron accelerators, for their own sake and as radiation sources. A controllable dual-wake injection scheme is put forward here to generate an ultrashort triplet electron bunch with high brightness and high polarization, employing a radially polarized laser as a driver. We find that the dual wakes can be driven by both transverse and longitudinal components of the laser field in the quasiblowout regime, sustaining the laser-modulated wakefield which facilitates the subcycle and transversely split injection of the triplet bunch. Polarization of the triplet bunch can be highly preserved due to the laser-assisted collective spin precession and the noncanceled transverse spins. In our three-dimensional particle-in-cell simulations, the triplet electron bunch, with duration about 500 as, six-dimensional brightness exceeding 10^{14} A/m^{2}/0.1% and polarization over 80%, can be generated using a few-terawatt laser. Such an electron bunch could play an essential role in many applications, such as ultrafast imaging, nuclear structure and high-energy physics studies, and the operation of coherent radiation sources.

2.
Phys Rev Lett ; 131(20): 202502, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-38039451

RESUMO

Traditional photonuclear reactions primarily excite giant dipole resonances, making the measurement of isovector giant resonances with higher multipolarities a great challenge. In this Letter, the manipulation of collective excitations of different multipole transitions in even-even nuclei via vortex γ photons is investigated. We develop the calculation method for photonuclear cross sections induced by the vortex γ photon beam using the fully self-consistent random-phase approximation plus particle-vibration coupling (RPA+PVC) model based on Skyrme density functional. We find that the electromagnetic transitions with multipolarity J<|m_{γ}| are forbidden for vortex γ photons due to the angular momentum conservation, with m_{γ} being the projection of total angular momentum of γ photon on its propagation direction. For instance, this allows for probing the isovector giant quadrupole resonance without interference from dipole transitions using vortex γ photons with m_{γ}=2. Furthermore, the electromagnetic transition with J=|m_{γ}|+1 vanishes at a specific polar angle. Therefore, the giant resonances with specific multipolarity can be extracted via vortex γ photons. Moreover, the vortex properties of γ photons can be meticulously diagnosed by measuring the nuclear photon-absorption cross section. Our method opens new avenues for photonuclear excitations, generation of coherent γ photon laser and precise detection of vortex particles, and consequently, has significant impact on nuclear physics, nuclear astrophysics and strong laser physics.

3.
Phys Rev Lett ; 131(17): 175101, 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37955489

RESUMO

We put forward a novel method for producing ultrarelativistic high-density high-polarization positrons through a single-shot interaction of a strong laser with a tilted solid foil. In our method, the driving laser ionizes the target, and the emitted electrons are accelerated and subsequently generate abundant γ photons via the nonlinear Compton scattering, dominated by the laser. These γ photons then generate polarized positrons via the nonlinear Breit-Wheeler process, dominated by a strong self-generated quasistatic magnetic field B^{S}. We find that placing the foil at an appropriate angle can result in a directional orientation of B^{S}, thereby polarizing positrons. Manipulating the laser polarization direction can control the angle between the γ photon polarization and B^{S}, significantly enhancing the positron polarization degree. Our spin-resolved quantum electrodynamics particle-in-cell simulations demonstrate that employing a laser with a peak intensity of about 10^{23} W/cm^{2} can obtain dense (≳10^{18} cm^{-3}) polarized positrons with an average polarization degree of about 70% and a yield of above 0.1 nC per shot. Moreover, our method is feasible using currently available or upcoming laser facilities and robust with respect to the laser and target parameters. Such high-density high-polarization positrons hold great significance in laboratory astrophysics, high-energy physics, and new physics beyond the standard model.

4.
World J Clin Cases ; 11(23): 5554-5558, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37637701

RESUMO

BACKGROUND: Jackstone is a rare entity of calculi in urinary tracts and has the characteristic appearance resembling toy jacks. They are nearly always reported to occur in the urinary bladder, we first report a rare case of jackstone located in the obstructed renal calyx. CASE SUMMARY: We report a 46-year-old man presenting with intermittent, painless gross hematuria and left flank pain. Urinary computed tomography revealed staghorn stones and secondary hydronephrosis. A jackstone with radiating branches was found in one of the dilated renal calyx. Percutaneous nephrolithotomy was performed and endoscopic images were recorded during the operation. Postoperative stone composition analysis revealed it as calcium oxalate monohydrate stones. CONCLUSION: Jackstones can occur in the renal collecting system besides the bladder. The unique appearance and imaging manifestations are the most important factors in the diagnosis of jackstones, and further exploration of the formation mechanism is required.

5.
Chem Biodivers ; 20(4): e202300025, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36898972

RESUMO

Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns and trigger an inflammatory response via the myeloid differential factor 88 (MyD88)-dependent and toll-interleukin-1 receptor domain-containing adapter-inducing interferon-ß (TRIF)-dependent pathways. Lindenane type sesquiterpene dimers (LSDs) are characteristic metabolites of plants belonging to the genus Sarcandra (Chloranthaceae). The aim of this study was to evaluate the potential anti-inflammatory effects of the LSDs shizukaol D (1) and sarcandrolide E (2) on lipopolysaccharides (LPS)-stimulated RAW264.7 macrophages in vitro, and explore the underlying mechanisms. Both LSDs neutralized the LPS-induced morphological changes and production of nitric oxide (NO), as determined by CCK-8 assay and Griess assay, respectively. Furthermore, shizukaol D (1) and sarcandrolide E (2) downregulated interferon ß (IFNß), tumor necrosis factor α (TNFα) and interleukin-1ß (IL-1ß) mRNA levels as measured by reverse transcription polymerase chain reaction (RT-PCR), and inhibited the phosphorylation of nuclear factor kappa B p65 (p65), nuclear factor kappa-Bα (IκBα), Jun N-terminal kinase (JNK), extracellular regulated kinase (ERK), mitogen-activated protein kinase p38 (p38), MyD88, IL-1RI-associated protein kinase 1 (IRAK1), and transforming growth factor-ß-activated kinase 1 (TAK1) proteins in the Western blotting assay. In conclusion, LSDs can alleviate the inflammatory response by inhibiting the TLR/MyD88 signalling pathway.


Assuntos
Inflamação , Sesquiterpenos , Receptores Toll-Like , Humanos , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Sesquiterpenos/farmacologia , Receptores Toll-Like/antagonistas & inibidores , Receptores Toll-Like/metabolismo
6.
World J Clin Cases ; 10(35): 12980-12989, 2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36569021

RESUMO

BACKGROUND: Urothelial encrusted pyelo-ureteritis disease is an infrequent condition and there is no unified surgical treatment and reference standard to consult. We have used a minimally invasive endoscopic method to treat three such cases, which yielded excellent results. CASE SUMMARY: The first case was a 45-year-old man who had unilateral ureteropelvic junction (UPJ) atresia and contralateral stenosis and was treated by double endoscopic surgery using an anterograde percutaneous nephroscope coupled with a rigid retrograde ureteroscope. The second case was a 12-year-old boy who received a percutaneous nephroscopy on one side and a percutaneous nephroscopy with a rigid ureteroscope on the other side due to the presence of bilateral UPJ stenosis. The third case was a 32-year-old woman with bilateral lower ureteral stricture treated using a rigid retrograde ureteroscope. Endoscopic surgeries were successfully performed on all the three patients. Varying degrees of encrustation and erosion of the urothelium were observed during the operation. The calcified layer composition analysis showed magnesium ammonium phosphate or carbonate apatite. Two patients achieved a good prognosis. CONCLUSION: Minimally invasive endoscopic treatment for urothelial encrusted pyelo-ureteritis disease can yield better results.

7.
Opt Lett ; 47(13): 3355-3358, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35776623

RESUMO

Circularly polarized (CP) γ-ray sources are versatile for broad applications in nuclear physics, high-energy physics, and astrophysics. The laser-plasma based particle accelerators provide accessibility for much higher flux γ-ray sources than conventional approaches, in which, however, the circular polarization properties of the emitted γ-photons are usually neglected. In this Letter, we show that brilliant CP γ-ray beams can be generated via the combination of laser plasma wakefield acceleration and plasma mirror techniques. In a weakly nonlinear Compton scattering scheme with moderate laser intensities, the helicity of the driving laser can be transferred to the emitted γ-photons, and their average polarization degree can reach ∼61% (20%) with a peak brilliance of ≳1021 photons/(s · mm2 · mrad2 · 0.1% BW) around 1 MeV (100 MeV). Moreover, our proposed method is easily feasible and robust with respect to the laser and plasma parameters.

8.
J Phys Chem Lett ; 13(19): 4272-4279, 2022 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35522820

RESUMO

Hydrogen bonds are ubiquitous in nature and of fundamental importance to the chemical and physical properties of molecular systems in the condensed phase. Nevertheless, our understanding of the structural and dynamical properties of hydrogen-bonded complexes in particular in electronic excited states remains very incomplete. Here, by using formic acid (FA) dimer as a prototype of DNA base pair, we investigate the ultrafast decay process initiated by removal of an electron from the inner-valence shell of the molecule upon electron-beam irradiation. Through fragment-ion and electron coincident momentum measurements and ab initio calculations, we find that de-excitation of an outer-valence electron at the same site can initiate ultrafast energy transfer to the neighboring molecule, which is in turn ionized through the emission of low-energy electrons. Our study reveals a concerted breaking of double hydrogen-bond in the dimer initiated by the ultrafast molecular rotations of two FA+ cations following this nonlocal decay mechanism.


Assuntos
Elétrons , Formiatos , Formiatos/química , Hidrogênio , Ligação de Hidrogênio
9.
Mil Med Res ; 9(1): 14, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35361280

RESUMO

Benign prostatic hyperplasia (BPH) is highly prevalent among older men, impacting on their quality of life, sexual function, and genitourinary health, and has become an important global burden of disease. Transurethral plasmakinetic resection of prostate (TUPKP) is one of the foremost surgical procedures for the treatment of BPH. It has become well established in clinical practice with good efficacy and safety. In 2018, we issued the guideline "2018 Standard Edition". However much new direct evidence has now emerged and this may change some of previous recommendations. The time is ripe to develop new evidence-based guidelines, so we formed a working group of clinical experts and methodologists. The steering group members posed 31 questions relevant to the management of TUPKP for BPH covering the following areas: questions relevant to the perioperative period (preoperative, intraoperative, and postoperative) of TUPKP in the treatment of BPH, postoperative complications and the level of surgeons' surgical skill. We searched the literature for direct evidence on the management of TUPKP for BPH, and assessed its certainty generated recommendations using the grade criteria by the European Association of Urology. Recommendations were either strong or weak, or in the form of an ungraded consensus-based statement. Finally, we issued 36 statements. Among them, 23 carried strong recommendations, and 13 carried weak recommendations for the stated procedure. They covered questions relevant to the aforementioned three areas. The preoperative period for TUPKP in the treatment of BPH included indications and contraindications for TUPKP, precautions for preoperative preparation in patients with renal impairment and urinary tract infection due to urinary retention, and preoperative prophylactic use of antibiotics. Questions relevant to the intraoperative period incorporated surgical operation techniques and prevention and management of bladder explosion. The application to different populations incorporating the efficacy and safety of TUPKP in the treatment of normal volume (< 80 ml) and large-volume (≥ 80 ml) BPH compared with transurethral urethral resection prostate, transurethral plasmakinetic enucleation of prostate and open prostatectomy; the efficacy and safety of TUPKP in high-risk populations and among people taking anticoagulant (antithrombotic) drugs. Questions relevant to the postoperative period incorporated the time and speed of flushing, the time indwelling catheters are needed, principles of postoperative therapeutic use of antibiotics, follow-up time and follow-up content. Questions related to complications incorporated types of complications and their incidence, postoperative leukocyturia, the treatment measures for the perforation and extravasation of the capsule, transurethral resection syndrome, postoperative bleeding, urinary catheter blockage, bladder spasm, overactive bladder, urinary incontinence, urethral stricture, rectal injury during surgery, postoperative erectile dysfunction and retrograde ejaculation. Final questions were related to surgeons' skills when performing TUPKP for the treatment of BPH. We hope these recommendations can help support healthcare workers caring for patients having TUPKP for the treatment of BPH.


Assuntos
Hiperplasia Prostática , Ressecção Transuretral da Próstata , Estreitamento Uretral , Idoso , Humanos , Masculino , Próstata , Hiperplasia Prostática/cirurgia , Qualidade de Vida , Ressecção Transuretral da Próstata/efeitos adversos , Ressecção Transuretral da Próstata/métodos , Estreitamento Uretral/etiologia , Estreitamento Uretral/cirurgia
10.
J Asian Nat Prod Res ; 24(11): 1025-1032, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34937451

RESUMO

Two new glycosides of methyl everninate, rhodomollosides A (1) and B (2), were isolated from the aerial parts of a medicinal plant Rhododendron molle. The structures of 1 and 2 were elucidated on the basis of detailed spectroscopic analyses as well as HPLC analyses for thiazolidine derivatives of their sugar moieties. The sugar moiety of rhodomolloside A (1) was elucidated to be a rare monosaccharide, D-allose, while rhodomolloside B (2) was assigned as a D-glucoside of methyl everninate. Furthermore, they were evaluated for their cytotoxicity against RAW264.7 cells, and for their inhibitory effects with a lipopolysaccharide (LPS)-stimulated murine macrophages RAW 264.7 cells model.


Assuntos
Diterpenos , Rhododendron , Camundongos , Animais , Rhododendron/química , Glicosídeos/farmacologia , Diterpenos/química , Estrutura Molecular , Açúcares , Componentes Aéreos da Planta
13.
Phys Rev Lett ; 124(1): 014801, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31976698

RESUMO

Generation of circularly polarized (CP) and linearly polarized (LP) γ rays via the single-shot interaction of an ultraintense laser pulse with a spin-polarized counterpropagating ultrarelativistic electron beam has been investigated in nonlinear Compton scattering in the quantum radiation-dominated regime. For the process simulation, a Monte Carlo method is developed which employs the electron-spin-resolved probabilities for polarized photon emissions. We show efficient ways for the transfer of the electron polarization to the high-energy photon polarization. In particular, multi-GeV CP (LP) γ rays with polarization of up to about 95% can be generated by a longitudinally (transversely) spin-polarized electron beam, with a photon flux meeting the requirements of recent proposals for the vacuum birefringence measurement in ultrastrong laser fields. Such high-energy, high-brilliance, high-polarization γ rays are also beneficial for other applications in high-energy physics, and laboratory astrophysics.

14.
Infect Drug Resist ; 12: 1073-1079, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31213854

RESUMO

Background: Mycoplasma is an opportunistic pathogen causing both urogenital and extragenital infections. The lack of cell wall renders Mycoplasma difficult to culture and identify with ordinary methods. Next-generation sequencing (NGS) is a new technology helping a lot in the diagnosis of infective diseases. In this case, NGS played a key role in the diagnosis of Mycoplasma infection. Case presentation: A mid-aged man suffering from renal cyst underwent cyst incision followed by invasive treatments to eliminate hematoma caused by renal artery hemorrhage. After the cyst incision operation, the patient had a persistent high temperature. The persistent increase of blood neutrophile granulocyte count and C-reaction protein suggested an unresolved infection. The empirically chosen anti-infective agents were meropenem and linezolid since the ordinary bacterial cultures of surgical site drainage and blood yielded a negative result. At postoperation day (POD) 17, NGS result of his drainage clearly indicated the pathogen was Mycoplasma hominis. At POD 24, the drug sensitivity test showed resistance to quinolones, clarithromycin and erythromycin, but intermediate to azithromycin. Since then, the antimicrobial agents were changed into azithromycin and kept unchanged until the patient was fully recovered and discharged at POD 39. Conclusion: When the ordinary laboratory diagnostic methods failed, NGS diagnosis could reduce the hospitalization expenses and shorten the lengths of hospital stay.

15.
Phys Rev Lett ; 122(15): 154801, 2019 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-31050500

RESUMO

Spin polarization of an ultrarelativistic electron beam head-on colliding with an ultraintense laser pulse is investigated in the quantum radiation-dominated regime. We develop a Monte Carlo method to model electron radiative spin effects in arbitrary electromagnetic fields by employing spin-resolved radiation probabilities in the local constant field approximation. Because of spin-dependent radiation reaction, the applied elliptically polarized laser pulse polarizes the initially unpolarized electron beam and splits it along the propagation direction into two oppositely transversely polarized parts with a splitting angle of about tens of milliradians. Thus, a dense electron beam with above 70% polarization can be generated in tensof femtoseconds with realistic laser pulses. The proposed method demonstrates a way for relativistic electron beam polarization with currently achievable laser facilities.

16.
Phys Rev Lett ; 121(7): 074801, 2018 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-30169078

RESUMO

Gamma-ray beams with a large angular momentum may affect astrophysical phenomena, which calls for appropriate earth-based experimental investigations. For this purpose, we investigate the generation of well-collimated γ-ray beams with a very large orbital angular momentum using nonlinear Compton scattering of a strong laser pulse of twisted photons at ultrarelativistic electrons. Angular momentum conservation among absorbed laser photons, quantum radiation, and electrons is numerically demonstrated in the quantum radiation-dominated regime. We point out that the angular momentum of the absorbed laser photons is not solely transferred to the emitted γ photons, but due to radiation reaction shared between the γ photons and interacting electrons. The efficiency of the angular momentum transfer is optimized with respect to the laser and electron beam parameters. The accompanying process of electron-positron pair production is furthermore shown to enhance the orbital angular momentum gained by the γ-ray beam.

18.
Nan Fang Yi Ke Da Xue Xue Bao ; 38(4): 443-449, 2018 Apr 20.
Artigo em Chinês | MEDLINE | ID: mdl-29735445

RESUMO

OBJECTIVE: To study the effects of intrahippocampal injection of cellular prion protein (PrPC) antibody on cognitive deficits of APPswe/PSEN1dE9 transgenic mice. METHODS: Eight-month-old male APPswe/PSEN1dE9 transgenic mice were subjected to bilateral intrahippocampal injection of a single dose (2 µL) of anti-PrPC monoclonal antibody (EP1802Y) or PBS, with wild-type C57Bl/6J mice serving as the control group. After two months, the mice were tested for cognitive behaviors using open filed (OF) test, Morris water maze (MWM) test, fear conditioning (FC) test, and novel object recognition (NOR) test, and immunohistochemistry was used to examine the changes in hippocampal expression of Aß1-42. RESULTS: The EP1802Y-treated and PBS-treated mice showed no significantly differences in the performance in OF test in terms of central activity time or total distance of activity (P>0.05), nor in NOR test in terms of novel object recognition index (P>0.05). In MWM test, the EP1802Y-treated and PBS-treated mice showed significantly reduced crossings of the hidden platform as compared with the wild-type mice (P<0.05), but EP1802Y-treated mice had a significantly shorter swimming distance to find the platform than PBS-treated mice (P<0.05). No significant differences were found in the results of FC test among the 3 groups. Immunohistochemistry revealed a significantly reduced expression of Aß1-42 in the hippocampus of EP1802Y-treated mice. CONCLUSION: Intrahippocampal injection of PrPC antibody can improve cognitive deficits of APPswe/PSEN1dE9 transgenic mice, which sheds light on a novel therapeutic approach for Alzheimer's disease that targets PrPC to lower the toxicity of Aß oligomer.


Assuntos
Anticorpos Monoclonais/farmacologia , Cognição/efeitos dos fármacos , Hipocampo , Doença de Alzheimer , Peptídeos beta-Amiloides , Animais , Modelos Animais de Doenças , Masculino , Aprendizagem em Labirinto , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fragmentos de Peptídeos , Proteínas Priônicas/imunologia
19.
Phys Rev Lett ; 120(12): 124803, 2018 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-29694059

RESUMO

The impact of the carrier-envelope phase (CEP) of an intense multicycle laser pulse on the radiation of an electron beam during nonlinear Compton scattering is investigated. We have identified a CEP effect specific to the ultrarelativistic regime. When the electron beam counterpropagates with the laser pulse, pronounced high-energy x-ray double peaks emerge near the backward direction relative to the initial electron motion. This is achieved in the relativistic interaction domain, where both the electron energy is required to be lower than for the electron reflection condition at the laser peak and the stochasticity effects in the photon emission need to be weak. The asymmetry parameter of the double peaks in the angular radiation distribution is shown to serve as a sensitive measure for the CEP of up to 10-cycle long laser pulses and can be applied for the characterization of extremely strong laser pulses in present and near future laser facilities.

20.
Int Urol Nephrol ; 50(3): 427-432, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29290000

RESUMO

PURPOSE: To compare efficacy, safety, and cost-effectiveness of fosfomycin tromethamine with other standard-of-care antibiotics in patients undergoing ureteroscopic lithotripsy. METHODS: This study was a prospective, multicenter, randomized, controlled trial. Eligible patients scheduled for ureteroscopic lithotripsy were randomly assigned to receive either fosfomycin (fosfomycin group, N = 101 patients) or standard-of-care antibiotic therapy as prophylaxis (control group, N = 115 patients). The incidence of infectious complications and adverse events was analyzed between the two groups, as well as the cost-benefit analysis. RESULTS: The incidence of infections following lithotripsy was 3.0% in the fosfomycin group and 6.1% in the control group (p > 0.05). Only asymptomatic bacteriuria was reported in fosfomycin group. In the control group was reported asymptomatic bacteriuria (3.5%), fever (0.9%), bacteremia (0.9%), and genitourinary infection (0.9%). The rate of adverse events was very low, with no adverse event reported in the fosfomycin group and only one in the control group (forearm phlebitis). The average cost per patient of antibiotic therapy with fosfomycin was 151.45 ± 8.62 yuan (22.7 ± 1.3 USD), significantly lower compared to the average cost per patient of antibiotics used in the control group 305.10 ± 245.95 yuan (45.7 ± 36.9 USD; p < 0.001). CONCLUSIONS: Two oral doses of 3 g fosfomycin tromethamine showed good efficacy and safety and low cost in perioperative prophylaxis of infections following ureteroscopic stone removal.


Assuntos
Antibacterianos/uso terapêutico , Antibioticoprofilaxia , Bacteriúria/prevenção & controle , Fosfomicina/uso terapêutico , Adulto , Antibacterianos/efeitos adversos , Antibacterianos/economia , Antibioticoprofilaxia/efeitos adversos , Antibioticoprofilaxia/economia , Bacteriemia/prevenção & controle , Análise Custo-Benefício , Feminino , Febre/prevenção & controle , Fosfomicina/efeitos adversos , Fosfomicina/economia , Humanos , Litotripsia/efeitos adversos , Masculino , Pessoa de Meia-Idade , Assistência Perioperatória , Estudos Prospectivos , Padrão de Cuidado/economia , Cálculos Ureterais/cirurgia , Ureteroscopia/efeitos adversos
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