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1.
J Endourol ; 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38661528

RESUMO

Introduction: Endoscopic tumor ablation of upper tract urothelial carcinoma (UTUC) allows for tumor control with the benefit of renal preservation but is impacted by intraoperative visibility. We sought to develop a computer vision model for real-time, automated segmentation of UTUC tumors to augment visualization during treatment. Materials and Methods: We collected 20 videos of endoscopic treatment of UTUC from two institutions. Frames from each video (N = 3387) were extracted and manually annotated to identify tumors and areas of ablated tumor. Three established computer vision models (U-Net, U-Net++, and UNext) were trained using these annotated frames and compared. Eighty percent of the data was used to train the models while 10% was used for both validation and testing. We evaluated the highest performing model for tumor and ablated tissue segmentation using a pixel-based analysis. The model and a video overlay depicting tumor segmentation were further evaluated intraoperatively. Results: All 20 videos (mean 36 ± 58 seconds) demonstrated tumor identification and 12 depicted areas of ablated tumor. The U-Net model demonstrated the best performance for segmentation of both tumors (area under the receiver operating curve [AUC-ROC] of 0.96) and areas of ablated tumor (AUC-ROC of 0.90). In addition, we implemented a working system to process real-time video feeds and overlay model predictions intraoperatively. The model was able to annotate new videos at 15 frames per second. Conclusions: Computer vision models demonstrate excellent real-time performance for automated upper tract urothelial tumor segmentation during ureteroscopy.

2.
J Phys Chem Lett ; 12(37): 8963-8971, 2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34506152

RESUMO

Cyanines are useful fluorophores for a myriad of biological labeling applications, but their interactions with biomolecules are unpredictable. Cyanine fluorescence intensity can be highly variable due to complex photoisomerization kinetics, which are exceedingly sensitive to the surrounding environment. This introduces large errors in Förster resonance energy transfer (FRET)-based experiments where fluorescence intensity is the output parameter. However, this environmental sensitivity is a strength from a biological sensing point of view if specific relationships between biomolecular structure and cyanine photophysics can be identified. We describe a set of DNA structures that modulate cyanine fluorescence intensity through the insertion of adenine or thymine bases. These structures simultaneously provide photophysical predictability and tunability. We characterize these structures using steady-state fluorescence measurements, fluorescence correlation spectroscopy (FCS), and time-resolved photoluminescence (TRPL). We find that the photoisomerization rate decreases over an order of magnitude across the adenine series, which is consistent with increasing immobilization of the cyanine moiety by the surrounding DNA structure.


Assuntos
Carbocianinas/química , DNA/química , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes/química , Isomerismo , Cinética , Conformação de Ácido Nucleico
3.
Cancer ; 127(2): 257-265, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33002197

RESUMO

BACKGROUND: Surgeons play a pivotal role in combating the opioid crisis that currently grips the United States. Changing surgeon behavior is difficult, and the degree to which behavioral science can steer surgeons toward decreased opioid prescribing is unclear. METHODS: This was a single-institution, single-arm, pre- and postintervention study examining the prescribing of opioids by urologists for adult patients undergoing prostatectomy or nephrectomy. The primary outcome was the quantity of opioids prescribed in oral morphine equivalents (OMEs) after hospital discharge. The primary exposure was a multipronged behavioral intervention designed to decrease opioid prescribing. The intervention had 3 components: 1) formal education, 2) individual audit feedback, and 3) peer comparison performance feedback. There were 3 phases to the study: a pre-intervention phase, an intervention phase, and a washout phase. RESULTS: Three hundred eighty-two patients underwent prostatectomy, and 306 patients underwent nephrectomy. The median OMEs decreased from 195 to 19 in the prostatectomy patients and from 200 to 0 in the nephrectomy patients (P < .05 for both). The median OMEs prescribed did not increase during the washout phase. Prostatectomy patients discharged with opioids had higher levels of anxiety than patients discharged without opioids (P < .05). Otherwise, prostatectomy and nephrectomy patients discharged with and without opioids did not differ in their perception of postoperative pain management, activity levels, psychiatric symptoms, or somatic symptoms (P > .05 for all). CONCLUSIONS: Implementing a multipronged behavioral intervention significantly reduced opioid prescribing for patients undergoing prostatectomy or nephrectomy without compromising patient-reported outcomes.


Assuntos
Analgésicos Opioides/administração & dosagem , Prescrições de Medicamentos/estatística & dados numéricos , Morfina/administração & dosagem , Nefrectomia , Manejo da Dor/métodos , Dor Pós-Operatória/tratamento farmacológico , Prostatectomia , Administração Oral , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Manejo da Dor/psicologia , Medidas de Resultados Relatados pelo Paciente , Cirurgiões/psicologia , Resultado do Tratamento , Estados Unidos , Urologistas/psicologia
4.
Neuromodulation ; 24(6): 1012-1017, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32762142

RESUMO

OBJECTIVES: To test the hypothesis that poststimulation block of nerve conduction can be achieved by low-frequency (≤1 kHz) biphasic stimulation (LFBS). MATERIALS AND METHODS: A tripolar cuff electrode was placed around the pudendal nerve in cats to deliver LFBS (1 kHz, 500 Hz, and 100 Hz). Two bipolar hook electrodes were placed central and distal to the cuff electrode to induce external urethral sphincter (EUS) contractions. A catheter was inserted into the urethra to record EUS contraction pressure. Pudendal nerve block by LFBS was confirmed by the failure of the central hook electrode stimulation to induce EUS contractions, while the distal hook electrode stimulation still induced contractions. RESULTS: Pudendal nerve conduction was completely blocked by LFBS at different frequencies (1 kHz, 500 Hz, and 100 Hz) after terminating LFBS. The post-LFBS block induced at the minimal stimulation intensity and duration was fully reversible within the same time period (10-15 min on average) for the three frequencies. However, the stimulation duration to induce block significantly (p < 0.05) increased from 23 ± 8 sec to 95 ± 14 sec when frequency increased from 100 Hz to 1 kHz. CONCLUSION: This study discovered that LFBS (≤1 kHz), like high-frequency (≥5 kHz) biphasic stimulation (HFBS), can induce poststimulation block. The result provides support for the theory that biphasic stimulation waveforms block axonal conduction by changing intracellular and extracellular ion concentrations. The post-LFBS block provides the opportunity to develop new neuromodulation devices for clinical applications where initial nerve firing is acceptable.


Assuntos
Bloqueio Nervoso , Nervo Pudendo , Animais , Gatos , Estimulação Elétrica , Masculino , Condução Nervosa , Uretra
5.
Urology ; 153: 124-128, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-32619594

RESUMO

OBJECTIVE: To determine predictors of success for sacral neuromodulation in women with overactive bladder, urinary retention, and fecal incontinence. METHODS: A retrospective chart review was performed on women who underwent a staged sacral neuromodulation implantation between 2007 and 2018. Clinical and procedural characteristics were recorded. Presence of intraoperative motor responses in either all 4 or <4 electrodes were used to group women. Endpoints included completion of stage II implant, tined lead revision, and patient-reported success. RESULTS: In 198 women with a mean age of 62.9 years (SD+/- 14.7), completion of stage II implant occurred in 92.4% of women, and 83.3% of these women reported success at the first postoperative visit. Continued success at 6 months was reported in 70.3%. Lead revision was noted in 23.0%. Age >65 years (odds ratio [OR] = 0.2, 95% confidence interval [CI] = 0.06-0.8) and prior onabotulinumtoxinA (onaBoNT-A) (OR = 0.2, 95% CI = 0.06-0.9) were negative predictors for completion of stage II implant on multivariable analysis. Also, prior pelvic floor physical therapy was a significant negative predictor of postoperative patient-reported success on multivariable analysis (OR = 0.25, 95% CI = 0.1-0.6). There were no differences seen in women who had motor responses with either all 4 electrodes or <4 electrodes in any endpoint (P > .05). CONCLUSION: Patient age >65 and history of prior onaBoNT-A were associated with failure to complete stage II implant. Women with prior pelvic floor physical therapy were less likely to report success after sacral neuromodulation. Motor responses in <4 electrodes during lead testing did not impact patient-reported success.


Assuntos
Incontinência Fecal , Diafragma da Pelve/fisiopatologia , Estimulação Elétrica Nervosa Transcutânea , Bexiga Urinária Hiperativa , Fatores Etários , Idoso , Eletrodos Implantados , Incontinência Fecal/fisiopatologia , Incontinência Fecal/terapia , Feminino , Humanos , Plexo Lombossacral/fisiologia , Pessoa de Meia-Idade , Medidas de Resultados Relatados pelo Paciente , Valor Preditivo dos Testes , Sacro , Estimulação Elétrica Nervosa Transcutânea/efeitos adversos , Estimulação Elétrica Nervosa Transcutânea/instrumentação , Estimulação Elétrica Nervosa Transcutânea/métodos , Resultado do Tratamento , Bexiga Urinária Hiperativa/fisiopatologia , Bexiga Urinária Hiperativa/terapia , Retenção Urinária/fisiopatologia , Retenção Urinária/terapia , Saúde da Mulher
6.
Neuromodulation ; 23(6): 747-753, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32840020

RESUMO

OBJECTIVE: To determine the relationship between various parameters of high-frequency biphasic stimulation (HFBS) and the recovery period of post-HFBS block of the pudendal nerve in cats. MATERIALS AND METHODS: A tripolar cuff electrode was implanted on the pudendal nerve to deliver HFBS in ten cats. Two hook electrodes were placed central or distal to the cuff electrode to stimulate the pudendal nerve and induce contractions of external urethral sphincter (EUS). A catheter was inserted toward the distal urethra to slowly perfuse the urethra and record the back-up pressure generated by EUS contractions. After determining the block threshold (T), HFBS (6 or 10 kHz) of different durations (1, 5, 10, 20, 30 min) and intensities (1T or 2T) was used to produce the post-HFBS block. RESULTS: HFBS at 10 kHz and 1T intensity must be applied for at least 30 min to induce post-HFBS block. However, 10 kHz HFBS at a higher intensity (2T) elicited post-HFBS block after stimulation of only 10 min; and 10 kHz HFBS at 2T for 30 min induced a longer-lasting (1-3 h) post-HFBS block that fully recovered with time. HFBS of 5-min duration at 6 kHz produced a longer period (20.4 ± 2.1 min, p < 0.05, N = 5 cats) of post-HFBS block than HFBS at 10 kHz (9.5 ± 2.1 min). CONCLUSION: HFBS of longer duration, higher intensity, and lower frequency can produce longer-lasting reversible post-HFBS block. This study is important for developing new methods to block nerve conduction by HFBS.


Assuntos
Estimulação Elétrica , Bloqueio Nervoso , Condução Nervosa , Nervo Pudendo , Uretra/inervação , Animais , Gatos , Feminino , Masculino
7.
J Neurophysiol ; 123(6): 2173-2179, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32374221

RESUMO

The purpose of this study was to examine the changes in cold block of unmyelinated C fibers in the tibial nerve by preconditioning with heating and to develop a safe method for thermal block of C-fiber conduction. In seven cats under α-chloralose anesthesia, C-fiber-evoked potentials elicited by electrical stimulation were recorded on the tibial nerve during block of axonal conduction induced by exposing a small segment (9 mm) of the nerve to cooling (from 35°C to ≤5°C) or heating (45°C). Before heating, partial, reproducible, and reversible cold block was first detected at a threshold cold block temperature of 15°C and complete cold block occurred at a temperature of ≤5°C. After the nerve was heated at 45°C for 5-35 min, the threshold cold block temperature significantly (P < 0.05) increased from 15°C to 25°C and the complete cold block temperature significantly (P < 0.05) increased from ≤5°C to 15°C on average. The increased cold block temperatures persisted for the duration of the experiments (30-100 min) while the amplitude of the C-fiber-evoked potential measured at 35°C recovered significantly (P < 0.05) to ~80% of control. This study discovered a novel thermal method to block mammalian C fibers at an elevated temperature (15-25°C), providing the opportunity to develop a thermal nerve block technology to suppress chronic pain of peripheral origin. The interaction between heating and cooling effects on C-fiber conduction indicates a possible interaction between different temperature-sensitive channels known to be present in the mammalian C fibers.NEW & NOTEWORTHY Our study discovered that the temperature range for producing a partial to complete cold block of mammalian C-fiber axons can be increased from 5-15°C to 15-25°C on average after a preheating at 45°C. This discovery raises many basic scientific questions about the influence of temperature on nerve conduction and block. It also raises the possibility of developing a novel implantable nerve block device to treat many chronic diseases including chronic pain.


Assuntos
Potenciais Evocados/fisiologia , Bloqueio Nervoso , Fibras Nervosas Amielínicas/fisiologia , Condução Nervosa/fisiologia , Temperatura , Nervo Tibial/fisiologia , Animais , Gatos , Feminino , Masculino
8.
Exp Neurol ; 329: 113301, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32251646

RESUMO

The goal of this study in anesthetized cats was to identify silent hypogastric nerve (HGN) afferent fibers that do not respond to bladder distention but become responsive after chemical irritation of the bladder. The HGN was split into multiple filaments small enough for recording action potentials from single or multiple afferent fibers. The bladder was distended by infusion of either saline or 0.5% acetic acid (AA) through a urethral catheter while recording intravesical pressure. A total of 90 HGN filaments from 17 cats responded to bladder distention with saline or AA. Three types of HGN afferents were identified. The first type was non-nociceptive mechano-sensitive that responded to bladder distention at normal physiological pressures (10-40 cmH2O). The second type was nociceptive mechano-sensitive that only responded to high-pressure (50-80 cmH2O) bladder distention with saline but responded to low-pressure bladder distention after sensitization with AA. The third type was chemo-sensitive nociceptive that was silent even during high-pressure bladder distention but after sensitization with AA did respond to low-pressure bladder distention. These results indicate that HGN afferents as well as pelvic nerve afferents may play a role in bladder nociception. The HGN afferent fibers that are silent during bladder distention at normal physiological pressures but become responsive after chemical irritation are important for understanding the possible pathophysiological mechanism underlying bladder allodynia in painful bladder syndrome.


Assuntos
Potenciais de Ação/fisiologia , Plexo Hipogástrico/fisiologia , Neurônios Aferentes/fisiologia , Doenças da Bexiga Urinária/fisiopatologia , Bexiga Urinária/inervação , Bexiga Urinária/fisiopatologia , Potenciais de Ação/efeitos dos fármacos , Vias Aferentes/efeitos dos fármacos , Vias Aferentes/fisiopatologia , Animais , Gatos , Feminino , Plexo Hipogástrico/efeitos dos fármacos , Masculino , Neurônios Aferentes/efeitos dos fármacos , Solução Salina/administração & dosagem , Solução Salina/efeitos adversos , Bexiga Urinária/efeitos dos fármacos , Doenças da Bexiga Urinária/induzido quimicamente
9.
Front Neurosci ; 14: 80, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32116523

RESUMO

OBJECTIVE: To determine the inhibitory effect on bladder activity induced by bilateral pudendal neuromodulation. METHODS: In 10 cats under anesthesia, two tripolar cuff electrodes were implanted bilaterally on the pudendal nerves for stimulation. A double lumen catheter was inserted into the bladder through the urethra to infuse saline and measure bladder pressure. During repeated cystometrograms (CMGs) pudendal nerve stimulation (PNS: 5 Hz, 0.2 ms, 5-15 min) was applied unilaterally or bilaterally at 1- or 2-times intensity threshold (T) for inducing anal sphincter twitching. PNS inhibition was indicated by the increase in bladder capacity measured by CMGs. RESULTS: Unilateral PNS at 1T did not significantly increase bladder capacity, but at 2T significantly (p < 0.05) increased bladder capacity by about 30%. Bilateral PNS at 1T also failed to increase bladder capacity, but at 2T significantly (p < 0.05) increased bladder capacity by about 60%, indicating an additive effect induced by the bilateral 2T PNS. Unilateral 1T PNS did not enhance the inhibitory effect induced by contra-lateral 2T PNS. CONCLUSION: This study in anesthetized cats reveals that an additive inhibition of reflex bladder activity can be induced by bilateral pudendal neuromodulation, indicating that bilateral PNS might achieve better therapeutic efficacy in treating overactive bladder (OAB) than unilateral PNS.

10.
Urology ; 140: 51-55, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32165276

RESUMO

OBJECTIVE: To identify whether institutions with strong conflicts of interest (COI) policies receive less industry payments than those with weaker policies. While industry-physician interactions can have collaborative benefits, financial COI can undermine preservation of the integrity of professional judgment and public trust. To address this concern, academic institutions have adopted COI policies. It is unclear whether the strength of COI policy correlates with industry payments in urology. MATERIALS AND METHODS: 131 US academic urology programs were surveyed on their COI policies, and graded according to the American Medical Student Association (AMSA) criteria. Strength of COI policy was compared against industry payments in the Center for Medicare and Medicaid Services Open Payments database. RESULTS: Fifty-seven programs responded to the survey, for a total response rate of 44%. There was no difference between COI policy groups on total hospital payments (P = .05), total department payments (P = .28), or dollars per payment (P = .57). On correlation analysis, there was a weak but statistically nonsignificant correlation between AMSA Industry Policy Survey Score and Open Payments payments (ρ = -0.14, P = .32). CONCLUSION: Strength of conflicts of interest policy in academic urology did not correlate to industry payments within the Open Payments database. Establishment of strong COI policy may create offsetting factors that mitigate the intended effects of the policy. Further studies will be required to develop the evidence base for policy design and implementation across various specialties.


Assuntos
Conflito de Interesses/economia , Conflito de Interesses/legislação & jurisprudência , Indústria Manufatureira/economia , Urologia/economia , Centers for Medicare and Medicaid Services, U.S. , Bases de Dados Factuais/economia , Bases de Dados Factuais/estatística & dados numéricos , Humanos , Relações Interinstitucionais , Indústria Manufatureira/ética , Inquéritos e Questionários/estatística & dados numéricos , Estados Unidos , Urologia/educação , Urologia/ética , Urologia/estatística & dados numéricos
11.
Urology ; 139: 90-96, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32006547

RESUMO

OBJECTIVES: To examine the distribution of industry payments to male and female academic urologists and the relationship between industry funding, academic rank, and scholarly impact. MATERIAL AND METHODS: Academic urologists from 131 programs with publicly available websites were compiled. Gender, rank, fellowship training, and scholarly impact metrics were recorded. Data from the 2016 Centers for Medicare and Medicaid Services Open Payments database were paired with faculty names. Comparisons were made using Fisher's Exact, Wilcoxon Rank Sum, and Spearman's Rank-Order tests. Multivariable logistic regression modeling identified predictors of receiving payments in the top quintile. RESULTS: Among 1,657 academic urologists, males comprised 84%. While there were no gender differences in the number of urologists listed in the Open Payments Database, males received more total funding (P < .001) and higher median general payments per capita (P < .03). Males also received higher proportions of research funding (P = .002), speaker fees (P = .03), education fees (P = .03) and higher median consulting fees (P = .003). Overall, males had higher scholarly impact (P < .001), which correlated with total industry payments (rho = 0.27, P < .001). Predictors of accepting the top quintile payments include male gender, associate professorship and H-index score ≥10. CONCLUSION: Most academic urologists accepted at least one industry payment in 2016, but males received more funding than females. There is a positive correlation between total industry payments, H-index, and total publications. More research is needed to understand why gender and scholarly productivity are associated with higher payouts. This is another important area that may influence career advancement and compensation for female urologists.


Assuntos
Mobilidade Ocupacional , Administração Financeira , Setor de Assistência à Saúde/economia , Fatores Sexuais , Urologistas , Sucesso Acadêmico , Feminino , Administração Financeira/métodos , Administração Financeira/estatística & dados numéricos , Humanos , Masculino , Medicare , Editoração/estatística & dados numéricos , Sexismo , Estados Unidos , Urologistas/economia , Urologistas/estatística & dados numéricos
12.
Chem Sci ; 11(27): 7226-7238, 2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34123008

RESUMO

In singlet fission (SF) the initially formed correlated triplet pair state, 1(TT), may evolve toward independent triplet excitons or higher spin states of the (TT) species. The latter result is often considered undesirable from a light harvesting perspective but may be attractive for quantum information sciences (QIS) applications, as the final exciton pair can be spin-entangled and magnetically active with relatively long room temperature decoherence times. In this study we use ultrafast transient absorption (TA) and time-resolved electron paramagnetic resonance (TR-EPR) spectroscopy to monitor SF and triplet pair evolution in a series of alkyl silyl-functionalized pentadithiophene (PDT) thin films designed with systematically varying pairwise and long-range molecular interactions between PDT chromophores. The lifetime of the (TT) species varies from 40 ns to 1.5 µs, the latter of which is associated with extremely weak intermolecular coupling, sharp optical spectroscopic features, and complex TR-EPR spectra that are composed of a mixture of triplet and quintet-like features. On the other hand, more tightly coupled films produce broader transient optical spectra but simpler TR-EPR spectra consistent with significant population in 5(TT)0. These distinctions are rationalized through the role of exciton diffusion and predictions of TT state mixing with low exchange coupling J versus pure spin substate population with larger J. The connection between population evolution using electronic and spin spectroscopies enables assignments that provide a more detailed picture of triplet pair evolution than previously presented and provides critical guidance for designing molecular QIS systems based on light-induced spin coherence.

13.
Nat Chem ; 12(1): 63-70, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31767991

RESUMO

Singlet fission promises to surpass the Shockley-Queisser limit for single-junction solar cell efficiency through the production of two electron-hole pairs per incident photon. However, this promise has not been fulfilled because singlet fission produces two low-energy triplet excitons that have been unexpectedly difficult to dissociate into free charges. To understand this phenomenon, we study charge separation from triplet excitons in polycrystalline pentacene using an electrochemical series of 12 different guest electron-acceptor molecules with varied reduction potentials. We observe separate optima in the charge yield as a function of driving force for singlet and triplet excitons, including inverted regimes for the dissociation of both states. Molecular acceptors can thus provide a strategic advantage to singlet fission solar cells by suppressing singlet dissociation at optimal driving forces for triplet dissociation. However, even at the optimal driving force, the rate constant for charge transfer from the triplet state is surprisingly small, ~107 s-1, presenting a previously unidentified obstacle to the design of efficient singlet fission solar cells.

14.
J Phys Chem B ; 123(41): 8628-8643, 2019 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-31553605

RESUMO

We report quantum chemical calculations using multireference perturbation theory (MRPT) with the density matrix renormalization group (DMRG) plus photothermal deflection spectroscopy measurements to investigate the manifold of carotenoid excited states and establish their energies relative to the bright state (S2) as a function of nuclear reorganization. We conclude that the primary photophysics and function of carotenoids are determined by interplay of only the bright (S2) and lowest-energy dark (S1) states. The lowest-lying dark state, far from being energetically distinguishable from the lowest-lying bright state along the entire excited-state nuclear reorganization pathway, is instead computed to be either the second or first excited state depending on what equilibrium geometry is considered. This result suggests that, rather than there being a dark intermediate excited state bridging a non-negligible energy gap from the lowest-lying dark state to the lowest-lying bright state, there is in fact no appreciable energy gap to bridge following photoexcitation. Instead, excited-state nuclear reorganization constitutes the bridge from S2 to S1, in the sense that these two states attain energetic degeneracy along this pathway.


Assuntos
Carotenoides/química , Teoria Quântica , Transferência de Energia , Modelos Moleculares , Estrutura Molecular , Fotoquímica
15.
Neurourol Urodyn ; 38(5): 1241-1249, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30947360

RESUMO

AIM: To validate the functionality of an implantable pudendal nerve stimulator under development for Food and Drug Administration approval to restore bladder function after spinal cord injury. METHODS: In nine cats under anesthesia, two tripolar cuff electrodes were implanted bilaterally on the pudendal nerves and one bipolar cuff electrode was implanted on the right pudendal nerve central to the tripolar cuff electrode. The pudendal nerve stimulator was implanted subcutaneously on the left lower back along the lumbosacral spine and connected to the cuff electrodes. In five cats, a double lumen catheter was inserted into the bladder through the urethra to infuse saline and measure bladder pressure and another catheter was inserted into the distal urethra to perfuse and measure the back pressure caused by urethral contraction. In four cats, a bladder catheter was inserted into the bladder dome and the urethra was left open so that voiding could occur without urethral outlet obstruction. RESULTS: The implantable pudendal nerve stimulator was controlled wirelessly and successfully provided the required stimulation waveforms to different cuff electrodes. Pudendal nerve stimulation (PNS) at 5 Hz increased bladder capacity to about 200% of control capacity. PNS at 20 to 30 Hz induced large (80-100 cmH2 O) bladder contractions under isovolumetric conditions. When combined with ipsilateral or bilateral pudendal nerve block induced by 6 to 10 kHz stimulation, PNS at 20 to 30 Hz elicited low pressure (<40 cmH 2 O) efficient (70%) voiding. CONCLUSIONS: The implantable stimulator generated the required stimulation waveforms and successfully induced low pressure efficient voiding in anesthetized cats.


Assuntos
Neuroestimuladores Implantáveis , Nervo Pudendo , Micção , Animais , Gatos , Estimulação Elétrica , Eletrodos Implantados , Contração Muscular , Uretra/fisiologia , Bexiga Urinária/fisiologia
16.
Am J Physiol Renal Physiol ; 316(4): F703-F711, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30672315

RESUMO

This study in α-chloralose-anesthetized cats revealed a role of hypogastric nerve afferent axons in nociceptive bladder activity induced by bladder irritation using 0.25% acetic acid (AA). In cats with intact hypogastric and pelvic nerves, AA irritation significantly ( P < 0.05) reduced bladder capacity to 45.0 ± 5.7% of the control capacity measured during a saline cystometrogram (CMG). In cats with the hypogastric nerves transected bilaterally, AA irritation also significantly ( P < 0.05) reduced bladder capacity, but the change was significantly smaller (capacity reduced to 71.5 ± 10.6% of saline control, P < 0.05) than that in cats with an intact hypogastric nerve. However, application of hypogastric nerve stimulation (HGNS: 20 Hz, 0.2 ms pulse width) to the central end of the transected nerves at an intensity (16 V) strong enough to activate C-fiber afferent axons facilitated the effect of AA irritation and further ( P < 0.05) reduced bladder capacity to 48.4 ± 7.4% of the saline control. This facilitation by HGNS was effective only at selected frequencies (1, 20, and 30 Hz) when the stimulation intensity was above the threshold for activating C-fibers. Tramadol (an analgesic agent) at 3 mg/kg iv completely blocked the nociceptive bladder activity and eliminated the facilitation by HGNS. HGNS did not alter non-nociceptive bladder activity induced by saline distention of the bladder. These results indicate that sympathetic afferents in the hypogastric nerve play an important role in the facilitation of the nociceptive bladder activity induced by bladder irritation that activates the silent C-fibers in the pelvic nerve.


Assuntos
Neurônios Aferentes/fisiologia , Nociceptividade/fisiologia , Sistema Nervoso Simpático/fisiologia , Bexiga Urinária/fisiologia , Ácido Acético , Analgésicos Opioides/farmacologia , Animais , Axônios/fisiologia , Gatos , Estimulação Elétrica , Feminino , Masculino , Fibras Nervosas Amielínicas/fisiologia , Neurônios Aferentes/efeitos dos fármacos , Nociceptividade/efeitos dos fármacos , Sistema Nervoso Simpático/efeitos dos fármacos , Tramadol/farmacologia
17.
Chem Sci ; 9(11): 3004-3013, 2018 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-29732084

RESUMO

We employ a combination of linear spectroscopy, electrochemistry, and transient absorption spectroscopy to characterize the interplay between electron transfer and singlet fission dynamics in polyacene-based dyes attached to nanostructured TiO2. For triisopropyl silylethynyl (TIPS)-pentacene, we find that the singlet fission time constant increases to 6.5 ps on a nanostructured TiO2 surface relative to a thin film time constant of 150 fs, and that triplets do not dissociate after they are formed. In contrast, TIPS-tetracene singlets quickly dissociate in 2 ps at the molecule/TiO2 interface, and this dissociation outcompetes the relatively slow singlet fission process. The addition of an alumina layer slows down electron injection, allowing the formation of triplets from singlet fission in 40 ps. However, the triplets do not inject electrons, which is likely due to a lack of sufficient driving force for triplet dissociation. These results point to the critical balance required between efficient singlet fission and appropriate energetics for interfacial charge transfer.

18.
J Phys Chem Lett ; 8(24): 6086-6091, 2017 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-29190427

RESUMO

The conjugated polymer poly(benzothiophene dioxide) (PBTDO1) has recently been shown to exhibit efficient intramolecular singlet fission in solution. We investigate the role of intermolecular interactions in triplet separation dynamics after singlet fission. We use transient absorption spectroscopy to determine the singlet fission rate and triplet yield in two polymers differing only by side-chain motif in both solution and the solid state. Whereas solid-state films show singlet fission rates identical to those measured in solution, the average lifetime of the triplet population increases dramatically and is strongly dependent on side-chain identity. These results show that it may be necessary to carefully engineer the solid-state microstructure of these "singlet fission polymers" to produce the long-lived triplets needed to realize efficient photovoltaic devices.

19.
J Am Acad Dermatol ; 75(3): 585-589, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27125531

RESUMO

BACKGROUND: Guided imagery and music can reportedly reduce pain and anxiety during surgery, but no comparative study has been performed for cutaneous surgery to our knowledge. OBJECTIVES: We sought to determine whether short-contact recorded guided imagery or relaxing music could reduce patient pain and anxiety, and surgeon anxiety, during cutaneous surgical procedures. METHODS: Subjects were adults undergoing excisional surgery for basal and squamous cell carcinoma. Randomization was to guided imagery (n = 50), relaxing music (n = 54), or control group (n = 51). Primary outcomes were pain and anxiety measured using visual analog scale and 6-item short-form of the State-Trait Anxiety Inventory, respectively. Secondary outcomes were anxiety of surgeons measured by the 6-item short-form of the State-Trait Anxiety Inventory and physical stress of patients conveyed by vital signs, respectively. RESULTS: There were no significant differences in subjects' pain, anxiety, blood pressure, and pulse rate across groups. In the recorded guided imagery and the relaxing music group, surgeon anxiety was significantly lower than in the control group. LIMITATIONS: Patients could not be blinded. CONCLUSION: Short-contact recorded guided imagery and relaxing music appear not to reduce patient pain and anxiety during excisional procedures under local anesthetic. However, surgeon anxiety may be reduced when patients are listening to such recordings.


Assuntos
Ansiedade/prevenção & controle , Procedimentos Cirúrgicos Dermatológicos/efeitos adversos , Imagens, Psicoterapia/métodos , Música/psicologia , Dor/prevenção & controle , Neoplasias Cutâneas/cirurgia , Adulto , Idoso , Ansiedade/etiologia , Carcinoma Basocelular/patologia , Carcinoma Basocelular/cirurgia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Procedimentos Cirúrgicos Dermatológicos/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Medição da Dor , Satisfação do Paciente/estatística & dados numéricos , Terapia de Relaxamento , Medição de Risco , Método Simples-Cego , Neoplasias Cutâneas/patologia , Cirurgiões/psicologia , Resultado do Tratamento
20.
J Spinal Cord Med ; 38(3): 326-34, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26010967

RESUMO

OBJECTIVE: To describe the development and psychometric properties of the SCI-QOL Psychological Trauma item bank and short form. DESIGN: Using a mixed-methods design, we developed and tested a Psychological Trauma item bank with patient and provider focus groups, cognitive interviews, and item response theory based analytic approaches, including tests of model fit, differential item functioning (DIF) and precision. SETTING: We tested a 31-item pool at several medical institutions across the United States, including the University of Michigan, Kessler Foundation, Rehabilitation Institute of Chicago, the University of Washington, Craig Hospital and the James J. Peters/Bronx Veterans Administration hospital. PARTICIPANTS: A total of 716 individuals with SCI completed the trauma items RESULTS: The 31 items fit a unidimensional model (CFI=0.952; RMSEA=0.061) and demonstrated good precision (theta range between 0.6 and 2.5). Nine items demonstrated negligible DIF with little impact on score estimates. The final calibrated item bank contains 19 items CONCLUSION: The SCI-QOL Psychological Trauma item bank is a psychometrically robust measurement tool from which a short form and a computer adaptive test (CAT) version are available.


Assuntos
Indicadores Básicos de Saúde , Qualidade de Vida , Traumatismos da Medula Espinal/psicologia , Estresse Psicológico/diagnóstico , Inquéritos e Questionários , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria , Traumatismos da Medula Espinal/complicações , Estresse Psicológico/classificação , Estresse Psicológico/etiologia
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