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1.
Radiology ; 310(3): e231473, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38441092

RESUMO

Background MRI-guided focal therapy (FT) allows for accurate targeting of localized clinically significant prostate cancer (csPCa) while preserving healthy prostate tissue, but the long-term outcomes of this approach require more study. Purpose To assess the 2-year oncological and functional outcomes of men with intermediate-risk prostate cancer (PCa) treated with targeted FT. Materials and Methods In this single-center prospective phase II trial, men with localized unifocal intermediate-risk PCa underwent transrectal MRI-guided focused ultrasound between July 2016 and July 2019. Planned ablation volumes included 10-mm margins when possible. Data regarding adverse events were collected and quality-of-life questionnaires were completed by participants at 6 weeks and at 5, 12, 18, and 24 months after treatment. Multiparametric MRI and targeted and systematic biopsies were performed at 24 months. Ablation volumes were determined by manual contouring of nonperfused volumes on immediate contrast-enhanced images. Generalized estimating equations were used to model trends in quality-of-life measures. Results Treatment was successfully completed in the 44 participants (median age, 67 years; IQR, 62-70 years; 36 patients with grade group [GG] 2; eight patients with GG 3). No major adverse events from treatment were recorded. One participant refused biopsy at 24 months. After 2 years, 39 of 43 participants (91%) had no csPCa at the treatment site and 36 of 43 (84%) had no cancer in the entire gland. No changes in International Index of Erectile Function-15 score or International Prostate Symptom Score were observed during 2-year follow-up (P = .73 and .39, respectively). Conclusion The majority of men treated with MRI-guided focused ultrasound for intermediate risk PCa had negative results for csPCa at biopsy 2 years after treatment. Additionally, there was no significant decline in quality of life per the validated questionnaires. Clinical trial registration no. NCT02968784 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Woodrum in this issue.


Assuntos
Imageamento por Ressonância Magnética Multiparamétrica , Neoplasias da Próstata , Masculino , Humanos , Idoso , Estudos Prospectivos , Qualidade de Vida , Imageamento por Ressonância Magnética , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/cirurgia
2.
Nat Commun ; 13(1): 6770, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36351922

RESUMO

The behavior of single layer van der Waals (vdW) materials is profoundly influenced by the immediate atomic environment at their surface, a prime example being the myriad of emergent properties in artificial heterostructures. Equally significant are adsorbates deposited onto their surface from ambient. While vdW interfaces are well understood, our knowledge regarding atmospheric contamination is severely limited. Here we show that the common ambient contamination on the surface of: graphene, graphite, hBN and MoS2 is composed of a self-organized molecular layer, which forms during a few days of ambient exposure. Using low-temperature STM measurements we image the atomic structure of this adlayer and in combination with infrared spectroscopy identify the contaminant molecules as normal alkanes with lengths of 20-26 carbon atoms. Through its ability to self-organize, the alkane layer displaces the manifold other airborne contaminant species, capping the surface of vdW materials and possibly dominating their interaction with the environment.

3.
Sci Adv ; 8(35): eabo6879, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36054359

RESUMO

In crystalline solids, the interactions of charge and spin can result in a variety of emergent quantum ground states, especially in partially filled, topological flat bands such as Landau levels or in "magic angle" graphene layers. Much less explored is rhombohedral graphite (RG), perhaps the simplest and structurally most perfect condensed matter system to host a flat band protected by symmetry. By scanning tunneling microscopy, we map the flat band charge density of 8, 10, 14, and 17 layers and identify a domain structure emerging from a competition between a sublattice antiferromagnetic insulator and a gapless correlated paramagnet. Our density matrix renormalization group calculations explain the observed features and demonstrate that the correlations are fundamentally different from graphene-based magnetism identified until now, forming the ground state of a quantum magnet. Our work establishes RG as a platform to study many-body interactions beyond the mean-field approach, where quantum fluctuations and entanglement dominate.

4.
Radiology ; 305(2): 390-398, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35852425

RESUMO

Background Multiparametric MRI has led to increased detection of clinically significant prostate cancer (csPCa). Micro-US is being investigated for csPCa detection. Purpose To compare multiparametric MRI and micro-US in detecting csPCa (grade group ≥2) and to determine the proportion of MRI nodules visible at micro-US for real-time targeted biopsy. Materials and methods This prospective, single-center trial enrolled biopsy-naive men with suspected prostate cancer (PCa) between May 2019 and September 2020. All patients underwent multiparametric MRI followed by micro-US; findings at both were interpreted in a blinded fashion, followed by targeted biopsy and nontargeted systematic biopsy using micro-US. Proportions were compared using the exact McNemar test. The differences in proportions were calculated. Results Ninety-four men (median age, 61 years; IQR, 57-68 years) were included. MRI- and micro-US-targeted biopsy depicted csPCa in 37 (39%) and 33 (35%) of the 94 men, respectively (P = .22); clinically insignificant PCa in 14 (15%) and 15 (16%) (P > .99); and cribriform and/or intraductal PCa in 14 (15%) and 13 (14%) (P > .99). The MRI- plus micro-US-targeted biopsy pathway depicted csPCa in 38 of the 94 (40%) men. The addition of nontargeted systematic biopsy to MRI- plus micro-US-targeted biopsy did not enable identification of any additional men with csPCa but did help identify nine additional men with clinically insignificant PCa (P = .04). Biopsy was avoided in 32 of the 94 men (34%) with MRI and nine of the 94 men (10%) with micro-US (P < .001). Among 93 MRI targets, 62 (67%) were prospectively visible at micro-US. Conclusion MRI and micro-US showed similar rates of prostate cancer detection, but more biopsies were avoided with the MRI pathway than with micro-US, with no benefit of adding nontargeted systematic biopsy to the MRI- plus micro-US-targeted biopsy pathway. Most MRI lesions were prospectively visible at micro-US, allowing real-time targeted biopsy. ClinicalTrials.gov registration no.: NCT03938376 © RSNA, 2022 Online supplemental material is available for this article.


Assuntos
Imageamento por Ressonância Magnética Multiparamétrica , Neoplasias da Próstata , Humanos , Masculino , Pessoa de Meia-Idade , Biópsia Guiada por Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Estudos Prospectivos , Próstata/diagnóstico por imagem , Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Idoso
5.
Eur Urol Focus ; 8(1): 112-120, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33583762

RESUMO

BACKGROUND: There is increasing interest in nonmorbid treatments for low- and intermediate-risk prostate cancer with fewer side effects than surgery or radiotherapy. OBJECTIVE: To investigate the tolerability, safety, and antitumor effects of the intraprostatic NanoZolid depot formulation Liproca Depot (LIDDS AB, Uppsala, Sweden) with antiandrogen 2-hydroxyflutamide (2-HOF) in men with low- or intermediate-risk localized prostate cancer managed with active surveillance. DESIGN, SETTING, AND PARTICIPANTS: This clinical phase 2b trial, LPC-004, involved 61 patients. The 2-HOF-containing formulation Liproca Depot was injected transrectally into the prostate under ultrasound guidance. A single dose of 35% or 45% of the prostate volume (study part 1) and a fixed dose of 16 or 20 ml (study part 2) of the formulation were evaluated. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES: The primary endpoints were tolerability and the reduction in serum prostate-specific antigen (PSA) 5 mo after injection. Antitumor effects were evaluated with magnetic resonance imaging (MRI) and prostate biopsies. Quality of life was assessed using a validated questionnaire (International Prostate Symptom Score). RESULTS AND LIMITATIONS: All doses were safe and well tolerated, without hormonal side effects. In part 2 of the study, the PSA reduction was greatest for the group receiving 16 ml, with an average decrease of 14%, and 95% of patients had a PSA reduction. Some 78% of patients showed a prostate volume decrease compared to baseline. Prostate MRI and biopsies confirmed stable or reduced lesion size. However, post treatment biopsies were performed at the discretion of the investigator, and not routinely. Most patients were amenable to a second injection. CONCLUSIONS: PSA and prostate volume decreased in most patients. Indications of efficacy were shown by post-treatment MRI and biopsies demonstrating stabilization or regression in the majority of cases. PATIENT SUMMARY: Liproca Depot is a safe, minimally invasive treatment that offers the potential for cancer control in patients with intermediate-risk prostate cancer. Further clinical evaluation is warranted.


Assuntos
Antígeno Prostático Específico , Neoplasias da Próstata , Antagonistas de Androgênios/uso terapêutico , Antagonistas de Receptores de Andrógenos/uso terapêutico , Humanos , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/tratamento farmacológico , Qualidade de Vida , Conduta Expectante
6.
Nat Nanotechnol ; 17(1): 61-66, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34782777

RESUMO

Quantum confinement of the charge carriers of graphene is an effective way to engineer its properties. This is commonly realized through physical edges that are associated with the deterioration of mobility and strong suppression of plasmon resonances. Here, we demonstrate a simple, large-area, edge-free nanostructuring technique, based on amplifying random nanoscale structural corrugations to a level where they efficiently confine charge carriers, without inducing significant inter-valley scattering. This soft confinement allows the low-loss lateral ultra-confinement of graphene plasmons, scaling up their resonance frequency from the native terahertz to the commercially relevant visible range. Visible graphene plasmons localized into nanocorrugations mediate much stronger light-matter interactions (Raman enhancement) than previously achieved with graphene, enabling the detection of specific molecules from femtomolar solutions or ambient air. Moreover, nanocorrugated graphene sheets also support propagating visible plasmon modes, as revealed by scanning near-field optical microscopy observation of their interference patterns.

8.
Radiology ; 298(3): 695-703, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33529137

RESUMO

Background To reduce adverse effects of whole-gland therapy, participants with localized clinically significant prostate cancer can undergo MRI-guided focal therapy. Purpose To explore safety and early oncologic and functional outcomes of targeted focal high-intensity focused ultrasound performed under MRI-guided focused ultrasound for intermediate-risk clinically significant prostate cancer. Materials and Methods In this prospective phase II trial, between February 2016 and July 2019, men with unifocal clinically significant prostate cancer visible at MRI were treated with transrectal MRI-guided focused ultrasound. The primary end point was the 5-month biopsy (last recorded in December 2019) with continuation to the 24-month follow-up projected to December 2021. Real-time ablation monitoring was performed with MR thermography. Nonperfused volume was measured at treatment completion. Periprocedural complications were recorded. Follow-up included International Prostate Symptom Score (IPSS) and International Index of Erectile Function-15 (IIEF-15) score at 6 weeks and 5 months, and multiparametric MRI and targeted biopsy of the treated area at 5 months. The generalized estimating equation model was used for statistical analysis, and the Holm method was used to adjust P value. Results Treatment was successfully completed in all 44 men, 36 with grade group (GG) 2 and eight with GG 3 disease (median age, 67 years; interquartile range [IQR], 62-70 years). No major treatment-related adverse events occurred. Forty-one of 44 participants (93%; 95% CI: 82, 98) were free of clinically significant prostate cancer (≥6 mm GG 1 disease or any volume ≥GG 2 disease) at the treatment site at 5-month biopsy (median, seven cores). Median IIEF-15 and IPSS scores were similar at baseline and at 5 months (IIEF-15 score at baseline, 61 [IQR, 34-67] and at 5 months, 53 [IQR, 24-65.5], P = .18; IPSS score at baseline, 3.5 [IQR, 1.8-7] and at 5 months, 6 [IQR, 2-7.3], P = .43). Larger ablations (≥15 cm3) compared with smaller ones were associated with a decline in IIEF-15 scores at 6 weeks (adjusted P < .01) and at 5 months (adjusted P = .07). Conclusion Targeted focal therapy of intermediate-risk prostate cancer performed with MRI-guided focused ultrasound ablation was safe and had encouraging early oncologic and functional outcomes. © RSNA, 2021 Online supplemental material is available for this article See also the editorial by Tempany-Afdhal in this issue.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade , Imagem por Ressonância Magnética Intervencionista/métodos , Neoplasias da Próstata/cirurgia , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Neoplasias da Próstata/diagnóstico por imagem
9.
Nano Lett ; 20(7): 5207-5213, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32551708

RESUMO

Quantum spin Hall (QSH) insulators host edge states, where the helical locking of spin and momentum suppresses backscattering of charge carriers, promising applications from low-power electronics to quantum computing. A major challenge for applications is the identification of large gap QSH materials, which would enable room temperature dissipationless transport in their edge states. Here we show that the layered mineral jacutingaite (Pt2HgSe3) is a candidate QSH material, realizing the long sought-after Kane-Mele insulator. Using scanning tunneling microscopy, we measure a band gap in excess of 100 meV and identify the hallmark edge states. By calculating the [Formula: see text] invariant, we confirm the topological nature of the gap. Jacutingaite is stable in air, and we demonstrate exfoliation down to at least two layers and show that it can be integrated into heterostructures with other two-dimensional materials. This adds a topological insulator to the 2D quantum material library.

11.
Nat Nanotechnol ; 13(5): 392-397, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29556008

RESUMO

Coherent manipulation of the binary degrees of freedom is at the heart of modern quantum technologies. Graphene offers two binary degrees: the electron spin and the valley. Efficient spin control has been demonstrated in many solid-state systems, whereas exploitation of the valley has only recently been started, albeit without control at the single-electron level. Here, we show that van der Waals stacking of graphene onto hexagonal boron nitride offers a natural platform for valley control. We use a graphene quantum dot induced by the tip of a scanning tunnelling microscope and demonstrate valley splitting that is tunable from -5 to +10 meV (including valley inversion) by sub-10-nm displacements of the quantum dot position. This boosts the range of controlled valley splitting by about one order of magnitude. The tunable inversion of spin and valley states should enable coherent superposition of these degrees of freedom as a first step towards graphene-based qubits.

12.
Sci Rep ; 7(1): 3035, 2017 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-28596579

RESUMO

Patterning graphene into various mesoscopic devices such as nanoribbons, quantum dots, etc. by lithographic techniques has enabled the guiding and manipulation of graphene's Dirac-type charge carriers. Graphene, with well-defined strain patterns, holds promise of similarly rich physics while avoiding the problems created by the hard to control edge configuration of lithographically prepared devices. To engineer the properties of graphene via mechanical deformation, versatile new techniques are needed to pattern strain profiles in a controlled manner. Here we present a process by which strain can be created in substrate supported graphene layers. Our atomic force microscope-based technique opens up new possibilities in tailoring the properties of graphene using mechanical strain.

13.
Can J Urol ; 24(3): 8802-8813, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28646935

RESUMO

INTRODUCTION: To report the five year results of a prospective, multi-center, randomized, blinded sham control trial of the Prostatic Urethral Lift (PUL) in men with bothersome lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: At 19 centers in North America and Australia, 206 subjects ≥ 50 years old with International Prostate Symptom Score (IPSS ) > 12, peak flow rate (Qmax) ≤ 12 mL/s, and prostate volume 30 cc-80 cc were randomized 2:1 to the PUL procedure or blinded sham control. In PUL permanent UroLift implants are placed to hold open the lateral lobes of the prostate to reduce urinary obstruction. After randomized comparison at 3 months and the only opportunity to add more PUL implants, PUL patients were followed to 5 years. LUTS severity (IPSS), quality of life (QOL), BPH Impact Index (BPHII), Qmax, sexual function, and adverse events were assessed throughout follow up. RESULTS: IPSS improvement after PUL was 88% greater than that of sham at 3 months. LUTS and QOL were significantly improved by 2 weeks with return to preoperative physical activity within 8.6 days. Improvement in IPSS, QOL, BPHII, and Qmax were durable through 5 years with improvements of 36%, 50%, 52%, and 44% respectively. No difference was seen between Intent to Treat and Per Protocol populations. Surgical retreatment was 13.6% over 5 years. Adverse events were mild to moderate and transient. Sexual function was stable over 5 years with no de novo, sustained erectile or ejaculatory dysfunction. CONCLUSIONS: PUL offers rapid improvement in symptoms, QOL and flow rate that is durable to 5 years. These improvements were achieved with minimal use of a postoperative urinary catheter, rapid return to normal, and preservation of both erectile and ejaculatory function. Symptom improvement was commensurate with patient satisfaction. PUL offers a minimally invasive option in the treatment of LUTS due to BPH.


Assuntos
Hiperplasia Prostática/complicações , Prostatismo/cirurgia , Próteses e Implantes , Método Duplo-Cego , Ejaculação , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos , Ereção Peniana , Estudos Prospectivos , Prostatismo/etiologia , Prostatismo/fisiopatologia , Qualidade de Vida , Reoperação , Índice de Gravidade de Doença , Sexualidade , Resultado do Tratamento , Urodinâmica
14.
Nano Lett ; 17(4): 2240-2245, 2017 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-28211276

RESUMO

One of the intriguing characteristics of honeycomb lattices is the appearance of a pseudomagnetic field as a result of mechanical deformation. In the case of graphene, the Landau quantization resulting from this pseudomagnetic field has been measured using scanning tunneling microscopy. Here we show that a signature of the pseudomagnetic field is a local sublattice symmetry breaking observable as a redistribution of the local density of states. This can be interpreted as a polarization of graphene's pseudospin due to a strain induced pseudomagnetic field, in analogy to the alignment of a real spin in a magnetic field. We reveal this sublattice symmetry breaking by tunably straining graphene using the tip of a scanning tunneling microscope. The tip locally lifts the graphene membrane from a SiO2 support, as visible by an increased slope of the I(z) curves. The amount of lifting is consistent with molecular dynamics calculations, which reveal a deformed graphene area under the tip in the shape of a Gaussian. The pseudomagnetic field induced by the deformation becomes visible as a sublattice symmetry breaking which scales with the lifting height of the strained deformation and therefore with the pseudomagnetic field strength. Its magnitude is quantitatively reproduced by analytic and tight-binding models, revealing fields of 1000 T. These results might be the starting point for an effective THz valley filter, as a basic element of valleytronics.

15.
Nano Lett ; 16(9): 5798-805, 2016 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-27466881

RESUMO

The electrostatic confinement of massless charge carriers is hampered by Klein tunneling. Circumventing this problem in graphene mainly relies on carving out nanostructures or applying electric displacement fields to open a band gap in bilayer graphene. So far, these approaches suffer from edge disorder or insufficiently controlled localization of electrons. Here we realize an alternative strategy in monolayer graphene, by combining a homogeneous magnetic field and electrostatic confinement. Using the tip of a scanning tunneling microscope, we induce a confining potential in the Landau gaps of bulk graphene without the need for physical edges. Gating the localized states toward the Fermi energy leads to regular charging sequences with more than 40 Coulomb peaks exhibiting typical addition energies of 7-20 meV. Orbital splittings of 4-10 meV and a valley splitting of about 3 meV for the first orbital state can be deduced. These experimental observations are quantitatively reproduced by tight binding calculations, which include the interactions of the graphene with the aligned hexagonal boron nitride substrate. The demonstrated confinement approach appears suitable to create quantum dots with well-defined wave function properties beyond the reach of traditional techniques.

16.
Can J Urol ; 22(3): 7772-82, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26068624

RESUMO

INTRODUCTION: To report the three year results of a multi-center, randomized, patient and outcome assessor blinded trial of the Prostatic Urethral Lift (PUL) in men with bothersome lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: At 19 centers in North America and Australia, 206 subjects = 50 years old with International Prostate Symptom Score (IPSS) ≥ 13, peak flow rate (Qmax) ≤ 12 mL/s, and prostate volume between 30 cc-80 cc were randomized 2:1 to the PUL procedure or sham control. PUL involved placing permanent UroLift implants into the lateral lobes of the prostate to enlarge the urethral lumen. After randomized comparison at 3 months, PUL patients were followed to 3 years. LUTS severity (IPSS), quality of life, Qmax, sexual function, and adverse events were assessed throughout follow up. RESULTS: The therapeutic effect of PUL regarding IPSS was 88% greater than sham at 3 months. Average improvements from baseline through 3 years were significant for total IPSS (41.1%), quality of life (48.8%), Qmax (53.1%), and individual IPSS symptoms. Symptomatic improvement was independent of prostate size. There were no de novo, sustained ejaculatory or erectile dysfunction events and all sexual function assessments showed average stability or improvement after PUL. Fifteen of the 140 patients originally randomized to PUL required surgical reintervention for treatment failure within the first 3 years. CONCLUSIONS: PUL offers rapid improvement in voiding and storage symptoms, quality of life and flow rate that is durable to 3 years. Patients demonstrated a level of symptom relief that is associated with significant patient satisfaction. PUL, a minimally invasive procedure, is very effective in treating bothersome LUTS secondary to benign prostatic obstruction (BPO) and is unique in its ability to preserve total sexual function while offering a rapid return to normal physical activities.


Assuntos
Próstata/patologia , Hiperplasia Prostática/complicações , Prostatismo/cirurgia , Próteses e Implantes , Uretra/cirurgia , Idoso , Idoso de 80 Anos ou mais , Cistoscopia , Método Duplo-Cego , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Hiperplasia Prostática/patologia , Prostatismo/etiologia , Prostatismo/fisiopatologia , Próteses e Implantes/efeitos adversos , Qualidade de Vida , Reoperação , Índice de Gravidade de Doença , Sexualidade , Resultado do Tratamento , Urodinâmica
17.
Urol Pract ; 2(1): 26-32, 2015 01.
Artigo em Inglês | MEDLINE | ID: mdl-37537806

RESUMO

INTRODUCTION: For a therapy to become an important part of a provider armamentarium it must be safer or better than existing therapies and be durable. The prostatic urethral lift offers rapid improvement in lower urinary tract symptoms associated with benign prostatic hyperplasia with minimal side effects. We report 2-year results of a multicenter, randomized, blinded trial of the prostatic urethral lift. METHODS: A total of 206 men 50 years old or older with an AUA-SI of 13 or greater, a peak flow rate of 12 ml per second or less and a 30 to 80 cc prostate were randomized 2:1 between the prostatic urethral lift and sham treatment. The prostatic urethral lift is performed by placing permanent transprostatic implants to lift apart the prostate lobes and reduce urethral obstruction. Sham treatment entailed rigid cystoscopy, a blinding screen and sounds that mimicked those of the prostatic urethral lift procedure. Patients were assessed for lower urinary tract symptoms, peak flow rate, quality of life and sexual function. RESULTS: The prostatic urethral lift reduced the AUA-SI 88% more than sham treatment (-11.1 vs -5.9, p = 0.003). Patients with the prostatic urethral lift experienced an AUA-SI reduction from 22.1 at baseline to 18.0 (-17%), 11.1 (-50%), 11.4 (-48%) and 12.5 (-42%) at 2 weeks, 3 months, and 1 and 2 years, respectively (p <0.0001). The peak flow rate was increased 4.2 ml per second at 3 months and 2 years (p <0.0001). By 2 years only 7.5% of patients required additional intervention for lower urinary tract symptoms. Adverse events were typically mild and transient. Encrustation did not develop on implants properly placed in the prostate. There was no occurrence of de novo sustained ejaculatory or erectile dysfunction. CONCLUSIONS: The prostatic urethral lift preserves sexual function and provides rapid improvement in symptoms, flow and quality of life that are sustained to 2 years.

18.
Nature ; 514(7524): 608-11, 2014 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-25355361

RESUMO

The possibility that non-magnetic materials such as carbon could exhibit a novel type of s-p electron magnetism has attracted much attention over the years, not least because such magnetic order is predicted to be stable at high temperatures. It has been demonstrated that atomic-scale structural defects of graphene can host unpaired spins, but it remains unclear under what conditions long-range magnetic order can emerge from such defect-bound magnetic moments. Here we propose that, in contrast to random defect distributions, atomic-scale engineering of graphene edges with specific crystallographic orientation--comprising edge atoms from only one sub-lattice of the bipartite graphene lattice--can give rise to a robust magnetic order. We use a nanofabrication technique based on scanning tunnelling microscopy to define graphene nanoribbons with nanometre precision and well-defined crystallographic edge orientations. Although so-called 'armchair' ribbons display quantum confinement gaps, ribbons with the 'zigzag' edge structure that are narrower than 7 nanometres exhibit an electronic bandgap of about 0.2-0.3 electronvolts, which can be identified as a signature of interaction-induced spin ordering along their edges. Moreover, upon increasing the ribbon width, a semiconductor-to-metal transition is revealed, indicating the switching of the magnetic coupling between opposite ribbon edges from the antiferromagnetic to the ferromagnetic configuration. We found that the magnetic order on graphene edges of controlled zigzag orientation can be stable even at room temperature, raising hopes of graphene-based spintronic devices operating under ambient conditions.

19.
J Urol ; 190(6): 2161-7, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23764081

RESUMO

PURPOSE: We report the first multicenter randomized blinded trial of the prostatic urethral lift for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia. MATERIALS AND METHODS: Men at least 50 years old with AUASI (American Urological Association Symptom Index) 13 or greater, a maximum flow rate 12 ml per second or less and a prostate 30 to 80 cc were randomized 2:1 between prostatic urethral lift and sham. In the prostatic urethral lift group small permanent implants are placed within the prostate to retract encroaching lobes and open the prostatic urethra. Sham entailed rigid cystoscopy with sounds mimicking the prostatic urethral lift. The primary end point was comparison of AUASI reduction at 3 months. The prostatic urethral lift arm subjects were followed to 1 year and assessed for lower urinary tract symptoms, peak urinary flow rate, quality of life and sexual function. RESULTS: A total of 206 men were randomized (prostatic urethral lift 140 vs sham 66). The prostatic urethral lift and sham AUASI was reduced by 11.1±7.67 and 5.9±7.66, respectively (p=0.003), thus meeting the primary end point. Prostatic urethral lift subjects experienced AUASI reduction from 22.1 baseline to 18.0, 11.0 and 11.1 at 2 weeks, 3 months and 12 months, respectively, p<0.001. Peak urinary flow rate increased 4.4 ml per second at 3 months and was sustained at 4.0 ml per second at 12 months, p<0.001. Adverse events were typically mild and transient. There was no occurrence of de novo ejaculatory or erectile dysfunction. CONCLUSIONS: The prostatic urethral lift, reliably performed with the patient under local anesthesia, provides rapid and sustained improvement in symptoms and flow, while preserving sexual function.


Assuntos
Sintomas do Trato Urinário Inferior/etiologia , Sintomas do Trato Urinário Inferior/cirurgia , Hiperplasia Prostática/complicações , Slings Suburetrais , Idoso , Método Duplo-Cego , Humanos , Masculino , Estudos Prospectivos
20.
Can J Urol ; 19(2): 6217-22, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22512970

RESUMO

Many men with benign prostatic hyperplasia (BPH) forego therapy because they are dissatisfied with current treatment options. While surgical resection and ablation using many different forms of energy remain the reference standard for BPH treatment, many men seek a less invasive technique that will improve symptoms but not risk the complications associated with tissue removal. The Prostatic Urethral Lift opens the prostatic urethra with UroLift (NeoTract Inc., Pleasanton, CA, USA) permanent implants that are delivered under cystoscopic visualization. The implants literally "hold open" the lateral prostatic lobes creating a passage through the obstructed prostatic urethra. Voiding and symptoms are significantly improved without the morbidity or possible complications following prostate resection. The entire procedure can be readily performed using local anesthesia. As with all new implant procedures, the technique has evolved with experience. The objective of this article is to describe the most current technique for the delivery of the UroLift implant in order to achieve maximal impact on symptom relief.


Assuntos
Hiperplasia Prostática/complicações , Prostatismo/cirurgia , Próteses e Implantes , Implantação de Prótese/métodos , Obstrução Uretral/cirurgia , Anestesia Local , Cistoscopia , Humanos , Masculino , Seleção de Pacientes , Prostatismo/etiologia , Implantação de Prótese/instrumentação , Obstrução Uretral/etiologia
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