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2.
Am J Physiol Lung Cell Mol Physiol ; 312(1): L79-L88, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27836901

RESUMO

In many mammals, including humans, removal of one lung (pneumonectomy) results in the compensatory growth of the remaining lung. Compensatory growth involves not only an increase in lung size, but also an increase in the number of alveoli in the peripheral lung; however, the process of compensatory neoalveolarization remains poorly understood. Here, we show that the expression of α-smooth muscle actin (SMA)-a cytoplasmic protein characteristic of myofibroblasts-is induced in the pleura following pneumonectomy. SMA induction appears to be dependent on pleural deformation (stretch) as induction is prevented by plombage or phrenic nerve transection (P < 0.001). Within 3 days of pneumonectomy, the frequency of SMA+ cells in subpleural alveolar ducts was significantly increased (P < 0.01). To determine the functional activity of these SMA+ cells, we isolated regenerating alveolar ducts by laser microdissection and analyzed individual cells using microfluidic single-cell quantitative PCR. Single cells expressing the SMA (Acta2) gene demonstrated significantly greater transcriptional activity than endothelial cells or other discrete cell populations in the alveolar duct (P < 0.05). The transcriptional activity of the Acta2+ cells, including expression of TGF signaling as well as repair-related genes, suggests that these myofibroblast-like cells contribute to compensatory lung growth.


Assuntos
Pulmão/crescimento & desenvolvimento , Miofibroblastos/metabolismo , Miofibroblastos/patologia , Estresse Mecânico , Actinas/metabolismo , Animais , Separação Celular , Regulação da Expressão Gênica no Desenvolvimento , Citometria por Imagem , Pulmão/metabolismo , Pulmão/cirurgia , Masculino , Camundongos Endogâmicos C57BL , Pneumonectomia , Reação em Cadeia da Polimerase , Análise de Célula Única , Transcrição Gênica
4.
Am J Physiol Lung Cell Mol Physiol ; 308(12): L1237-44, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-26078396

RESUMO

In most mammals, removing one lung (pneumonectomy) results in the compensatory growth of the remaining lung. In mice, stereological observations have demonstrated an increase in the number of mature alveoli; however, anatomic evidence of the early phases of alveolar growth has remained elusive. To identify changes in the lung microstructure associated with neoalveolarization, we used tissue histology, electron microscopy, and synchrotron imaging to examine the configuration of the alveolar duct after murine pneumonectomy. Systematic histological examination of the cardiac lobe demonstrated no change in the relative frequency of dihedral angle components (Ends, Bends, and Junctions) (P > 0.05), but a significant decrease in the length of a subset of septal ends ("E"). Septal retraction, observed in 20-30% of the alveolar ducts, was maximal on day 3 after pneumonectomy (P < 0.01) and returned to baseline levels within 3 wk. Consistent with septal retraction, the postpneumonectomy alveolar duct diameter ratio (Dout:Din) was significantly lower 3 days after pneumonectomy compared to all controls except for the detergent-treated lung (P < 0.001). To identify clumped capillaries predicted by septal retraction, vascular casting, analyzed by both scanning electron microscopy and synchrotron imaging, demonstrated matted capillaries that were most prominent 3 days after pneumonectomy. Numerical simulations suggested that septal retraction could reflect increased surface tension within the alveolar duct, resulting in a new equilibrium at a higher total energy and lower surface area. The spatial and temporal association of these microstructural changes with postpneumonectomy lung growth suggests that these changes represent an early phase of alveolar duct remodeling.


Assuntos
Neovascularização Fisiológica , Pneumonectomia , Alvéolos Pulmonares/irrigação sanguínea , Alvéolos Pulmonares/crescimento & desenvolvimento , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica de Varredura , Tensão Superficial , Síncrotrons , Tomografia Computadorizada por Raios X
5.
Cancer Control ; 22(3): 335-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26351890

RESUMO

BACKGROUND: The adoption of minimally invasive approaches to the management of esophageal disease has been slow, except for the laparoscopic management of gastroesophageal reflux disease. However, the advent of new surgical technologies - in particular, robotic-assisted surgical systems - has revolutionized esophageal surgery. METHODS: The literature was systematically reviewed using the keywords "robotic," "esophageal surgery," "esophagectomy," "fundoplication," and "esophageal myotomy." The reference lists from these articles were then also analyzed. RESULTS: Forty-nine studies were included in our comprehensive review of robotic-assisted esophageal surgery, and they consisted of literature reviews, case reports, retrospective and prospective case series, and randomized controlled trials. CONCLUSIONS: Robotic-assisted esophageal surgery is a safe and effective way of treating esophageal disorders, including gastroesophageal reflux disease, achalasia, leiomyomas, and cancer. The use of robotic surgical systems has many benefits for managing disorders of the esophagus, but more studies, including randomized controlled trials, are necessary.


Assuntos
Doenças do Esôfago/cirurgia , Esofagectomia/métodos , Fundoplicatura/métodos , Procedimentos Cirúrgicos Robóticos/métodos , Neoplasias Esofágicas/cirurgia , Humanos
6.
Microvasc Res ; 95: 60-7, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24984292

RESUMO

Vascular systems grow and remodel in response to not only metabolic needs, but also mechanical influences as well. Here, we investigated the influence of tissue-level mechanical forces on the patterning and structure of the chick chorioallantoic membrane (CAM) microcirculation. A dipole stretch field was applied to the CAM using custom computer-controlled servomotors. The topography of the stretch field was mapped using finite element models. After 3days of stretch, Sholl analysis of the CAM demonstrated a 7-fold increase in conducting vessel intersections within the stretch field (p<0.01). The morphometric analysis of intravital microscopy and scanning electron microscopy (SEM) images demonstrated that the increase vessel density was a result of an increase in interbranch distance (p<0.01) and a decrease in bifurcation angles (p<0.01); there was no significant increase in conducting vessel number (p>0.05). In contrast, corrosion casting and SEM of the stretch field capillary meshwork demonstrated intense sprouting and intussusceptive angiogenesis. Both planar surface area (p<0.05) and pillar density (p<0.01) were significantly increased relative to control regions of the CAM. We conclude that a uniaxial stretch field stimulates the axial growth and realignment of conducting vessels as well as intussusceptive and sprouting angiogenesis within the gas exchange capillaries of the ex ovo CAM.


Assuntos
Capilares/fisiologia , Membrana Corioalantoide/irrigação sanguínea , Mecanotransdução Celular , Neovascularização Fisiológica , Animais , Capilares/ultraestrutura , Embrião de Galinha , Molde por Corrosão , Análise de Elementos Finitos , Microcirculação , Microscopia Eletroquímica de Varredura , Microscopia de Fluorescência , Microscopia de Vídeo , Modelos Cardiovasculares , Estresse Mecânico , Fatores de Tempo
7.
Am Surg ; 90(7): 1909-1912, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38520291

RESUMO

The modified Graham patch repair is a well-established technique for management of perforating foregut injuries, often learned by surgeons during general surgery training. There is, however, little to no data regarding the utilization of this technique for perforation of the distal midgut or in the re-operative field. We present two cases of midgut anastomotic complications successfully managed with modified graham patch repair at our institution. The first case is a 79-year-old female who underwent an emergent right hemicolectomy at an outside institution for management of an iatrogenic perforation during endoscopic polypectomy. Over the course of two years she underwent numerous abdominal operations, due to various complications, ultimately resulting in multiple resections and end ileostomy creation. She then had her ileostomy reversed by laparoscopic single incision (SILS) technique at our institution. This was also complicated by anastomotic leak. Intraoperatively, adequate mobilization of the anastomosis for resection was deemed not safe due to dense fibrosis and adhesions in the re-operative field; therefore, she underwent a SILS modified Graham patch repair of an ileocolic anastomotic defect with diverting loop ileostomy. Post-operatively, she had no radiographic evidence of leak from the repaired anastomosis, which facilitated successful loop ileostomy reversal five months later. Our second case is a 64-year-old male referred to our institution for management of his stage IV colon cancer. He underwent an open right hemicolectomy and hepatic metastectomy, which was complicated by anastomotic leak. The small defect was repaired via a SILS modified Graham patch technique. Five months postoperatively, he had neither radiographic nor endoscopic evidence of a leak; therefore, he successfully underwent ileostomy reversal without complication. We encourage further investigation and reporting of the role of the modified graham patch repair in management of midgut anastomotic complications, particularly when resection and re-anastomosis is unsafe due to a hostile re-operative field.


Assuntos
Anastomose Cirúrgica , Fístula Anastomótica , Humanos , Feminino , Idoso , Fístula Anastomótica/cirurgia , Fístula Anastomótica/etiologia , Masculino , Pessoa de Meia-Idade , Ileostomia , Intestino Delgado/cirurgia , Colectomia/métodos , Laparoscopia , Perfuração Intestinal/cirurgia , Perfuração Intestinal/etiologia
8.
Fertil Steril ; 121(1): 126-127, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37813274

RESUMO

OBJECTIVE: To present the use of robotic-integrated ultrasound for performing a double discoid excision of multifocal rectosigmoid endometriosis. DESIGN: Video article. STATEMENT OF CONSENT: The patient included in this video gave consent for publication of the video and posting of the video online, including social media, journal website, scientific literature websites (such as PubMed, ScienceDirect, Scopus), and other applicable sites. PATIENT: A 26-year-old G0 woman with chronic pelvic pain, dyschezia, and dysmenorrhea refractory to medical management desired future fertility. Imaging was suggestive of deep infiltrating endometriosis involving the rectosigmoid colon. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Double discoid excision of multifocal rectosigmoid endometriosis using robotic-integrated ultrasound. RESULTS: Not applicable. CONCLUSIONS: Performing a complete preoperative evaluation in patients with suspected endometriosis is important for determining the extent of disease and necessity of a multidisciplinary approach. Robotic-integrated ultrasound can provide additional information, including the size and depth of bowel endometriosis lesions, which can play a role in surgical decision making. Performing a double discoid excision of multifocal rectosigmoid endometriosis using robotic-integrated ultrasound is a technique that can avoid the need for a segmental bowel resection.


Assuntos
Endometriose , Procedimentos Cirúrgicos Robóticos , Adulto , Feminino , Humanos , Colo Sigmoide/cirurgia , Endometriose/diagnóstico por imagem , Endometriose/cirurgia , Endometriose/patologia , Reto/diagnóstico por imagem , Reto/cirurgia , Reto/patologia
9.
J Robot Surg ; 18(1): 82, 2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-38367193

RESUMO

Robotic surgery may decrease surgeon stress compared to laparoscopic. To evaluate intraoperative surgeon stress, we measured salivary alpha-amylase and cortisol. We hypothesized robotic elicited lower increases in surgeon salivary amylase and cortisol than laparoscopic. Surgical faculty (n = 7) performing laparoscopic and robotic operations participated. Demographics: age, years in practice, time using laparoscopic vs robotic, comfort level and enthusiasm for each. Operative data included operative time, WRVU (surgical "effort"), resident year. Saliva was collected using passive drool collection system at beginning, middle and end of each case; amylase and cortisol measured using ELISA. Standard values were created using 7-minute exercise (HIIT), collecting saliva pre- and post-workout. Linear regression and Student's t test used for statistical analysis; p values < 0.05 were significant. Ninety-four cases (56 robotic, 38 laparoscopic) were collected (April-October 2022). Standardized change in amylase was 8.4 ± 4.5 (p < 0.001). Among operations, raw maximum amylase change in laparoscopic and robotic was 23.4 ± 11.5 and 22.2 ± 13.4; raw maximum cortisol change was 44.21 ± 46.57 and 53.21 ± 50.36, respectively. Values normalized to individual surgeon HIIT response, WRVU, and operative time, showing 40% decrease in amylase in robotic: 0.095 ± 0.12, vs laparoscopic: 0.164 ± 0.16 (p < 0.02). Normalized change in cortisol was: laparoscopic 0.30 ± 0.44, robotic 0.22 ± 0.4 (p = NS). On linear regression (p < 0.001), surgeons comfortable with complex laparoscopic cases had lower change in normalized amylase (p < 0.01); comfort with complex robotic was not significant. Robotic may be less physiologically stressful, eliciting less increase in salivary amylase than laparoscopic. Comfort with complex laparoscopic decreased stress in robotic, suggesting laparoscopic experience is valuable prior to robotic.


Assuntos
Laparoscopia , Procedimentos Cirúrgicos Robóticos , Cirurgiões , Humanos , Procedimentos Cirúrgicos Robóticos/métodos , Hidrocortisona/análise , Amilases
10.
Med Care ; 51(8): 654-8, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23703649

RESUMO

BACKGROUND: Limited health literacy is a barrier for understanding health information and has been identified as a risk factor for overuse of the emergency department (ED). The association of health literacy with access to primary care services in patients presenting to the ED has not been fully explored. OBJECTIVE: To examine the relationship between health literacy, access to primary care, and reasons for ED use among adults presenting for emergency care. METHODS: Structured interviews that included health literacy assessment were performed involving 492 ED patients at one Southern academic medical center. Unadjusted and multivariable logistic regression models assessed the relationship between health literacy and (1) access to a personal physician; (2) doctor office visits; (3) ED visits; (4) hospitalizations; and (5) potentially preventable hospital admissions. RESULTS: After adjusting for sociodemographic and health status, those with limited health literacy reported fewer doctor office visits [odds ratio (OR)=0.6; 95% confidence interval (CI), 0.4-1.0], greater ED use, (OR=1.6; 95% CI, 1.0-2.4), and had more potentially preventable hospital admissions (OR=1.7; 95% CI, 1.0-2.7) than those with adequate health literacy. After further controlling for insurance and employment status, fewer doctor office visits remained significantly associated with patient health literacy (OR=0.5; 95% CI, 0.3-0.9). Patients with limited health literacy reported a preference for emergency care, as the services were perceived as better. CONCLUSIONS: Among ED patients, limited health literacy was independently associated with fewer doctor office visits and a preference for emergency care. Policies to reduce ED use should consider steps to limit barriers and improve attitudes toward primary care services.


Assuntos
Serviço Hospitalar de Emergência/estatística & dados numéricos , Conhecimentos, Atitudes e Prática em Saúde , Letramento em Saúde/estatística & dados numéricos , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Atenção Primária à Saúde/estatística & dados numéricos , Centros Médicos Acadêmicos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Visita a Consultório Médico/estatística & dados numéricos , Estados Unidos
11.
Am Surg ; 89(7): 3301-3302, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36853905

RESUMO

Many transanal platforms have recently evolved to manage rectal pathologies. Transanal endoscopic microsurgery (TEM) and transanal laparoscopic minimally invasive surgery (TAMIS) have been developed to address the limitations of conventional transanal surgery. More recently, the addition of the robotic platform to the surgeon's armamentarium has made it possible to combine the dexterity of the robotic surgical system with the standard TAMIS single-port platform to treat complex rectal lesions. In this article, we present the case of a patient who underwent rTAMIS for the management of a large endoscopically unresectable rectal mass.


Assuntos
Adenoma , Neoplasias Gastrointestinais , Neoplasias Retais , Procedimentos Cirúrgicos Robóticos , Robótica , Cirurgia Endoscópica Transanal , Humanos , Neoplasias Retais/cirurgia , Adenoma/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos , Canal Anal
12.
Am Surg ; 89(7): 3207-3208, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36789989

RESUMO

Syphilis is associated with 3 stages of infection-primary, secondary, and tertiary-each with their own associated clinical findings. Secondary syphilis manifests with condyloma lata and other cutaneous findings, and typically occurs several months after the initial infection. Condyloma lata are primarily found in the genital area, but may also be found in other locations such as the umbilicus, axilla, and neck. This brief report describes an umbilical condyloma lata discovered in a patient with secondary syphilis and HIV co-infection and discusses surgical excision and fulguration as an option for definitive management.


Assuntos
Infecções por HIV , Sífilis Cutânea , Sífilis , Humanos , Umbigo/cirurgia , Sífilis/complicações , Sífilis Cutânea/complicações , Infecções por HIV/complicações
13.
Cureus ; 15(9): e45636, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37868432

RESUMO

Here, we discuss a case of a 42-year-old premenopausal female who presented with chronic pelvic pain and recurrent small bowel obstruction during menstruation. The patient reported a nine-year history of pelvic pain and a four-year history of episodic small bowel obstruction requiring multiple prior inpatient admissions. During these admissions, the obstruction was managed conservatively with bowel rest and nasogastric tube placement; however, symptoms would recur with subsequent menstrual cycles. Computed tomography showed diffusely dilated loops of small bowel with a transition point in the central anterior pelvis, and magnetic resonance enterography revealed a mass-like area involving small bowel loops in the mid pelvis. The patient underwent laparoscopic surgical intervention including bowel resection with re-anastomosis, hysterectomy, bilateral salpingectomy, and left oophorectomy. Intraoperative findings included severe distention of the proximal bowel with a discrete deep endometriosis lesion of the terminal ileum which was confirmed on final pathologic examination. This case emphasizes the importance of considering endometriosis as the etiology of recurrent catamenial small bowel obstruction, particularly in premenopausal women.

14.
J Robot Surg ; 17(6): 2823-2830, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37743399

RESUMO

Diverticulitis is a prevalent gastrointestinal disease that often warrants surgical intervention. However, the optimal approach between traditional laparoscopy (LC) and robotic-assisted laparoscopy (RAC) for diverticulitis remains unclear. Our research compares these techniques in patients diagnosed with left-sided diverticulitis treated at a single, tertiary referral center from 2019 to 2022. Among the 134 patients, 86 underwent laparoscopic and 48 robotic-assisted surgeries. The surgeries included in this analysis are left colectomy, sigmoid colectomy, low anterior resection, and Hartmann's procedure. Primary outcomes were major morbidity and 30-day mortality. Secondary outcomes were operative time, conversion to open, length of stay, unplanned return to the operating room, 30-day readmission rate, and overall morbidity. While demographics and comorbidities were similar for both groups, the robotic-assisted group displayed a statistically significant longer operative time (198.0 ± 84.4 LC vs. 264.8 ± 78.5 min RAC, p < 0.001). When investigated further, there was a significant difference in operative time for uncomplicated diverticulitis cases favoring the LC approach (169.17 ± 58.1 LC vs. 244.82 ± 58.79 min RAC, p < 0.001). This significant difference, however, was not present in complicated diverticulitis cases. Other factors, such as overall and major morbidity, rate of conversion to open approach, ostomy creation, estimated blood loss, time to return of bowel function, length of stay, and 30-day readmission rate, did not significantly differ between the groups. There was no 30-day mortality in either group. Favorable patient outcomes, lack of significant difference in operative time compared with traditional laparoscopy, and absence of differences in morbidities or efficacy, raises an interesting question in the world of minimally invasive surgery: is the robotic-assisted approach emerging as the advantageous approach for complicated diverticulitis cases? We encourage additional, multi-center analysis of specifically complicated diverticulitis managed with both surgical approaches to investigate if these findings are replicated outside of our institution.


Assuntos
Diverticulite , Laparoscopia , Procedimentos Cirúrgicos Robóticos , Robótica , Humanos , Procedimentos Cirúrgicos Robóticos/métodos , Diverticulite/cirurgia , Colectomia/métodos , Laparoscopia/métodos , Estudos Retrospectivos , Resultado do Tratamento , Tempo de Internação , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/cirurgia
15.
Inorg Chem ; 51(18): 9748-56, 2012 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-22937801

RESUMO

This work describes a comprehensive assignment of the vibrational spectra of the platinum(II) diimine bisthiolate and chloride complexes as a prototype structure for a diversity of Pt(II) diimine chromophores. The dynamics and energy dissipation pathways in excited states of light harvesting molecules relies largely on the coupling between the high frequency and the low frequency modes. As such, the assignment of the vibrational spectrum of the chromophore is of utmost importance, especially in the low-frequency region, below 500 cm(-1), where the key metal-ligand framework modes occur. This region is experimentally difficult to access with infrared spectroscopy and hence frequently remains elusive. However, this region is easily accessible with Raman and inelastic neutron scattering (INS) spectroscopies. Accordingly, a combination of inelastic neutron scattering and Raman spectroscopy with the aid of computational results from periodic-DFT and the mode visualizations, as well as isotopic substitution, allowed for an identification of the modes that contain significant contributions from Pt-Cl, Pt-S, and Pt-N stretch modes. The results also demonstrate that it is not possible to assign transition energies to "pure", localized modes in the low frequency region, as a consequence of the anticipated severe coupling that occurs among the skeletal modes. The use of INS has proved invaluable in identifying and assigning the modes in the lowest frequency region, and overall the results will be of assistance in analyzing the structure of the electronic excited state in the families of chromophores containing a Pt(diimine) core.

16.
Chemistry ; 17(16): 4385-95, 2011 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-21433129

RESUMO

We introduce a new highly efficient photochromic organometallic dithienylethene (DTE) complex, the first instance of a DTE core symmetrically modified by two Pt(II) chromophores [Pt(PEt(3))(2)(C≡C)(DTE)(C≡C)Pt(PEt(3))(2)Ph] (1), which undergoes ring-closure when activated by visible light in solvents of different polarity, in thin films and even in the solid state. Complex 1 has been synthesised and fully photophysically characterised by (resonance) Raman and transient absorption spectroscopy complemented by calculations. The ring-closing photoconversion in a single crystal of 1 has been followed by X-ray crystallography. This process occurs with the extremely high yield of 80%--considerably outperforming the other DTE derivatives. Remarkably, the photocyclisation of 1 occurs even under visible light (>400 nm), which is not absorbed by the non-metallated DTE core HC≡C(DTE)C≡CH (2) itself. This unusual behaviour and the high photocyclisation yields in solution are attributed to the presence of a heavy atom in 1 that enables a triplet-sensitised photocyclisation pathway, elucidated by transient absorption spectroscopy and DFT calculations. The results of resonance Raman investigation confirm the involvement of the alkynyl unit in the frontier orbitals of both closed and open forms of 1 in the photocyclisation process. The changes in the Raman spectra upon cyclisation have permitted the identification of Raman marker bands, which include the acetylide stretching vibration. Importantly, these bands occur in the spectral region unobstructed by other vibrations and can be used for non-destructive monitoring of photocyclisation/photoreversion processes and for optical readout in this type of efficiently photochromic thermally stable systems. This study indicates a strategy for generating efficient solid-state photoswitches in which modification of the Pt(II) units has the potential to tune absorption properties and hence operational wavelength across the visible range.

17.
Chem Commun (Camb) ; 57(16): 2093-2096, 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33514992

RESUMO

Transition metal complexes offer cost-effective alternatives as hole-transport materials (HTMs) in perovskite solar cells. However, the devices suffer from low performance. We boost the power conversion efficiency of devices with transition metal complex HTMs from 2% to above 10% through energy level tuning. We further demonstrate the excellent photostability of the device based on the additive-free HTM.

18.
Inorg Chem ; 49(21): 10041-56, 2010 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-20873855

RESUMO

A series of mononuclear complexes of the type [Pt(Bu(2)cat)(4,4'-R(2)-bipy)] [where Bu(2)cat is the dianion of 3,5-(t)Bu(2)-catechol and R = H, (t)Bu, or C(O)NEt(2)] and analogous dinuclear complexes based on the "back-to-back" bis-catechol ligand 3,3',4,4'-tetrahydroxybiphenyl have been studied in detail in both their ground and excited states by a range of physical methods including electrochemistry, UV/vis/near-IR, IR, and electron paramagnetic resonance spectroelectrochemistry, and time-resolved IR (TRIR) and transient absorption (TA) spectroscopy. Density functional theory calculations have been performed to support these studies, which provide a detailed picture of the ground- and excited-state electronic structures, and excited-state dynamics, of these complexes. Notable observations include the following: (i) for the first time, the lowest-energy catecholate → bipyridine (bpy) ligand-to-ligand charge-transfer (LL'CT) excited states of these chromophores have been studied by TRIR spectroscopy, showing a range of transient bands associated with the bpy radical anion and semiquinone species, and back-electron-transfer occurring in hundreds of picoseconds; (ii) strong electronic coupling between the two catecholate units in the bridging ligand of the dinuclear complexes results in a delocalized, planar (class 3) "mixed-valence" catecholate(2-)/semiquinone(•-) state formed by one-electron oxidation of the bridging ligand; (iii) in the LL'CT excited state of the dinuclear complexes, the bridging ligand is symmetrical and delocalized, whereas the bpy radical anion is localized at one terminus of the complex. This study is the first example of an investigation of excited-state behavior in platinum(II) catecholate complexes, performed with the use of picosecond TRIR and femtosecond TA spectroscopy.


Assuntos
Catecóis/química , Compostos Organoplatínicos/química , Teoria Quântica , Catecóis/síntese química , Cristalografia por Raios X , Eletroquímica , Modelos Moleculares , Estrutura Molecular , Compostos Organoplatínicos/síntese química , Oxirredução , Espectrofotometria Infravermelho , Fatores de Tempo , Vibração
19.
Front Med (Lausanne) ; 7: 112, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32373614

RESUMO

Lung regeneration occurs in a variety of adult mammals after surgical removal of one lung (pneumonectomy). Previous studies of murine post-pneumonectomy lung growth have identified regenerative "hotspots" in subpleural alveolar ducts; however, the cell-types participating in this process remain unclear. To identify the single cells participating in post-pneumonectomy lung growth, we used laser microdissection, enzymatic digestion and microfluidic isolation. Single-cell transcriptional analysis of the murine alveolar duct cells was performed using the C1 integrated fluidic circuit (Fluidigm) and a custom PCR panel designed for lung growth and repair genes. The multi-dimensional data set was analyzed using visualization software based on the tSNE algorithm. The analysis identified 6 cell clusters; 1 cell cluster was present only after pneumonectomy. This post-pneumonectomy cluster was significantly less transcriptionally active than 3 other clusters and may represent a transitional cell population. A provisional cluster identity for 4 of the 6 cell clusters was obtained by embedding bulk transcriptional data into the tSNE analysis. The transcriptional pattern of the 6 clusters was further analyzed for genes associated with lung repair, matrix production, and angiogenesis. The data demonstrated that multiple cell-types (clusters) transcribed genes linked to these basic functions. We conclude that the coordinated gene expression across multiple cell clusters is likely a response to a shared regenerative microenvironment within the subpleural alveolar ducts.

20.
RSC Adv ; 9(63): 36771-36787, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-35539033

RESUMO

Carbons have been synthesized through the reduction of molten carbonate systems under varied conditions. The mechanism and kinetics of carbon electrodeposition has been investigated. Carbon morphologies include amorphous, graphite-like, and spherical aggregate phases. Increased graphitic character is observed in carbons electrodeposited at more cathodic potentials, particularly at higher temperatures. Bonding has been investigated and oxygen functionalised sp2 and sp3 structures have been identified. The level of functionalization decreases in carbons with reduced amorphous and increased graphitic character. Thermal decomposition of electrodepositied carbons has been investigated and zero order kinetics have been identified. A relationship has been identified between elevated oxygen functionalization and increased pseudo-capacitance, with carbons deposited at 0.15 A cm-2 showing capacitances of 400 F g-1 in 0.5 M H2SO4 at sweep rates of 10 mV s-1.

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