767 research outputs found
Large K-exciton dynamics in GaN epilayers: the non-thermal and thermal regime
We present a detailed investigation concerning the exciton dynamics in GaN
epilayers grown on c-plane sapphire substrates, focussing on the exciton
formation and the transition from the nonthermal to the thermal regime. The
time-resolved kinetics of LO-phonon replicas is used to address the energy
relaxation in the excitonic band. From ps time-resolved spectra we bring
evidence for a long lasting non-thermal excitonic distribution which accounts
for the rst 50 ps. Such a behavior is con rmed in di erent experimental
conditions, both when non-resonant and resonant excitation are used. At low
excitation power density the exciton formation and their subsequent
thermalization is dominated by impurity scattering rather than by acoustic
phonon scattering. The estimate of the average energy of the excitons as a
function of delay after the excitation pulse provides information on the
relaxation time, which describes the evolution of the exciton population to the
thermal regime.Comment: 9 pages,8 figure
Transumbilical versus transvaginal retrieval of surgical specimens at laparoscopy: a randomized trial.
Objective
We sought to compare transumbilical (TU) and transvaginal (TV) route for retrieval of surgical specimens at laparoscopy.
Study design
Women scheduled for a laparoscopic resection of an adnexal mass were randomized to have their surgical specimen removed either through a posterior colpotomy (n = 34) or the umbilical port site (n = 32). Group allocation was concealed from patients and bedside clinicians. The primary outcome was postoperative incisional pain assessed by a 10-cm visual analog scale at 1, 3, and 24 hours after surgery.
Results
TV retrieval caused less postoperative pain than TU specimen extraction at each time point (visual analog scale score at 1 hour: 2.6 \ub1 2.9 vs 1.2 \ub1 2.0, P = .03; at 3 hours: 2.4 \ub1 2.0 vs 1.4 \ub1 2.0, P = .02; and at 24 hours: 1.1 \ub1 1.5 vs 0.5 \ub1 1.4, P = .02). A higher proportion of women in the TU group than in the TV group indicated the umbilicus as the most painful area at 1 and 3 hours postoperatively. Two months after surgery, the participants scored similarly as to their overall satisfaction, cosmetic outcome, and dyspareunia upon resumption of intercourse.
Conclusion
A TV approach for specimen removal after laparoscopic resection of adnexal masses offers the advantage of less postoperative pain than TU retrieva
Medicinal plants and their bacterial microbiota: A review on antimicrobial compounds production for plant and human health
Medicinal plants (MPs) have been used since antiquity in traditional and popular medicine, and they represent a very important source of bioactive molecules, including antibiotic, antiviral, and antifungal molecules. Such compounds are often of plant origin, but in some cases, an origin or a modification from plant microbiota has been shown. Actually, the research continues to report the production of bioactive molecules by plants, but the role of plantâendophytic interaction is emerging. Classic examples are mainly concerned with fungal endophytes; however, it has been recently shown that bacterial endophytes can also play an important role in influencing the plant metabolism related to the synthesis of bioactive compounds. In spite of this, a deep investigation on the power of MP bacterial endophytes is lacking. Here, an overview of the studies on MP bacterial microbiota and its role in the production of plant antimicrobial compounds contributing to prime host defense system and representing a huge resource for biotech and therapeutic applications is provided
Medicinal Plants and Their Bacterial Microbiota: A Review on Antimicrobial Compounds Production for Plant and Human Health
Medicinal plants (MPs) have been used since antiquity in traditional and popular medicine, and they represent a very important source of bioactive molecules, including antibiotic, antiviral, and antifungal molecules. Such compounds are often of plant origin, but in some cases, an origin or a modification from plant microbiota has been shown. Actually, the research continues to report the production of bioactive molecules by plants, but the role of plant–endophytic interaction is emerging. Classic examples are mainly concerned with fungal endophytes; however, it has been recently shown that bacterial endophytes can also play an important role in influencing the plant metabolism related to the synthesis of bioactive compounds. In spite of this, a deep investigation on the power of MP bacterial endophytes is lacking. Here, an overview of the studies on MP bacterial microbiota and its role in the production of plant antimicrobial compounds contributing to prime host defense system and representing a huge resource for biotech and therapeutic applications is provided
Eradication of isolated para-aortic nodal recurrence in a patient with an advanced high grade sorous ovarian carcinoma: our experience and review of literature
Abstract: We report a case report regarding the eradication of isolated lymph-nodal para-aortic recurrence
in the aortic region down the left renal vein (LRV) in a patient treated two years earlier in
another hospital for a FIGO stage IC2 high-grade serous ovarian carcinoma with a video showing
the para-aortic space after eradication of the metastatic tissue. A 66 year-old woman was admitted
24 months after the initial surgical procedure for an increased Ca 125 level and CT scan that revealed
a 3 cm para-aortic infrarenal lymph-nodal recurrence that was confirmed by PET/CT scan. A secondary
cytoreductive surgery (SCS) with a para-aortic lymph-nodal dissection of the tissue down
the LRV and radical omentectomy were performed: during the cytoreduction, the right hemicolon
was mobilized. The anterior surface of the inferior vena cava (IVC), aorta and LRV were exposed.
The metastatic lymph nodes were detected in the para-ortic space down the proximal part of the
LRV and eradicated; an en bloc infrarenal lymph-node dissection from the aortocaval region was
performed. The operative time during the surgical procedure was 212 min with a blood loss of 120
mL. No intra- and postoperative complications, including ureteral or vascular injury or renal dysfunction,
occurred. At histological examination, three dissected lymph nodes were positive for metastasis,
and the patient was discharged five days after laparotomy without side effects and underwent
chemotherapy 3 weeks later; after a follow-up of 42 months, no recurrence was detected. In
conclusion, secondary debulking surgery can be considered a safe and effective therapeutic option
for the management of recurrences, although long-term follow-ups are necessary to evaluate the
overall oncologic outcomes of this procedure
Artificial intelligence weights the importance of factors predicting complete cytoreduction at secondary cytoreductive surgery for recurrent ovarian cancer
Objective: Accumulating evidence support that complete cytoreduction (CC) at the time of secondary cytoreductive surgery (SCS) improves survival in patients affected by recurrent ovarian cancer (ROC). Here, we aimed to determine whether artificial intelligence (AI) might be useful in weighting the importance of clinical variables predicting CC and survival.
Methods: This is a retrospective study evaluating 194 patients having SCS for ROC. Using artificial neuronal network (ANN) analysis was estimated the importance of different variables, used in predicting CC and survival. ANN simulates a biological neuronal system. Like neurons, ANN acquires knowledge through a learning-phase process and allows weighting the importance of covariates, thus establishing how much a variable influences a multifactor phenomenon.
Results: Overall, 82.9% of patients had CC at the time of SCS. Using ANN, we observed that the 3 main factors driving the ability of achieve CC included: disease-free interval (DFI) (importance: 0.231), retroperitoneal recurrence (importance: 0.178), residual disease at primary surgical treatment (importance: 0.138), and International Federation of Gynecology and Obstetrics (FIGO) stage at presentation (importance: 0.088). Looking at connections between different covariates and overall survival (OS), we observed that DFI is the most important variable influencing OS (importance: 0.306). Other important variables included: CC (importance: 0.217), and FIGO stage at presentation (importance: 0.100).
Conclusion: According to our results, DFI should be considered as the most important factor predicting both CC and OS. Further studies are needed to estimate the clinical utility of AI in providing help in decision making process
Efficacy and fertility outcomes of levonorgestrel-releasing intra-uterine system treatment for patients with atypical complex hyperplasia or endometrial cancer: A retrospective study
Objective: To investigate the efficacy of levonorgestrel-releasing intra-uterine system (LNG-IUS) treatment in patients affected by atypical complex hyperplasia/endometrial cancer (ACH/EC) wishing to preserve their fertility and to present fertility outcomes of those patients who actively tried to conceive. Methods: Data of consecutive women with ACH/EC who underwent fertility-sparing treatment using LNG-IUS were retrospectively evaluated. Results: Overall, 48 patients and the mean (\ub1standard deviation) length of follow-up was 82.6\ub147.2 months. Among patients with ACH, 25/28 (89.3%) had a complete response (CR), 2/28 (7.1%) had a partial response (PR) and 1/28 (3.6%) had a progressive disease (PD). Mean (\ub1standard deviation) time to CR was 6.7\ub14.0 months. Among patients with G1 EC, 13/16 (81.3%) had a CR, 1/16 (6.3%) had a PR and 2/16 (12.5%) had a PD. Mean (\ub1standard deviation) time to CR was 5.0\ub12.9 months. Among patients with G2 EC, 3/4 (75.0%) had a CR and 1/4 (25.0%) had a PD. Mean (\ub1standard deviation) time to CR was 4.0\ub10 months. Only 19 (39.6%) patients who had CR actually attempted to conceive. Eleven (57.9%) women tried to conceive naturally while 8 (42.1%) women underwent an in vitro fertilization (IVF). Fourteen (73.7%) patients wishing to conceive achieved a pregnancy (6 spontaneously and 8 through IVF). Conclusions: Fertility-sparing treatment of patient with ACH/EC with LNG-IUS achieves high regression rates and good fertility outcomes. Future larger multi-institutional studies should be designed to confirm these preliminary findings
Benzoâextended cyclohepta[def]fluorene derivatives with very lowâlying triplet states
Open-shell non-alternant polycyclic hydrocarbons (PHs) are attracting increasing attention due to their promising applications in organic spintronics and quantum computing. Herein we report the synthesis of three cyclohepta[def]fluorene-based diradicaloids (1â3), by fusion of benzo rings on its periphery for the thermodynamic stabilization, as evidenced by multiple characterization techniques. Remarkably, all of them display a very narrow optical energy gap (Egopt=0.52â0.69â
eV) and persistent stability under ambient conditions (t1/2=11.7â33.3â
h). More importantly, this new type of diradicaloids possess a low-lying triplet state with an extremely small singletâtriplet energy gap, as low as 0.002â
kcalâmolâ1, with a clear dependence on the molecular size. This family of compounds thus offers a new route to create non-alternant open-shell PHs with high-spin ground states, and opens up novel possibilities and insights into understanding the structureâproperty relationships
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