Time-optimal trajectories to circumsolar space using solar electric propulsion

The aim of this paper is to explore the capabilities of a solar electric propelled spacecraft on a mission towards circumsolar space. Using an indirect approach, the paper investigates minimum time of transfer (direct) trajectories from an initial heliocentric parking orbit to a desired final heliocentric target orbit, with a low perihelion radius and a high orbital inclination. The simulation results are then collected into graphs and tables for a trade-off analysis of the main mission parameters. Finally, a comparison of the performance between a solar electric and a (photonic) solar sail based spacecraft is discussed

Gene profiling, biomarkers and pathways characterizing HCV-related hepatocellular carcinoma

<p>Abstract</p> <p>Background</p> <p>Hepatitis C virus (HCV) infection is a major cause of hepatocellular carcinoma (HCC) worldwide. The molecular mechanisms of HCV-induced hepatocarcinogenesis are not yet fully elucidated. Besides indirect effects as tissue inflammation and regeneration, a more direct oncogenic activity of HCV can be postulated leading to an altered expression of cellular genes by early HCV viral proteins. In the present study, a comparison of gene expression patterns has been performed by microarray analysis on liver biopsies from HCV-positive HCC patients and HCV-negative controls.</p> <p>Methods</p> <p>Gene expression profiling of liver tissues has been performed using a high-density microarray containing 36'000 oligos, representing 90% of the human genes. Samples were obtained from 14 patients affected by HCV-related HCC and 7 HCV-negative non-liver-cancer patients, enrolled at INT in Naples. Transcriptional profiles identified in liver biopsies from HCC nodules and paired non-adjacent non-HCC liver tissue of the same HCV-positive patients were compared to those from HCV-negative controls by the Cluster program. The pathway analysis was performed using the BRB-Array- Tools based on the "Ingenuity System Database". Significance threshold of <it>t</it>-test was set at 0.001.</p> <p>Results</p> <p>Significant differences were found between the expression patterns of several genes falling into different metabolic and inflammation/immunity pathways in HCV-related HCC tissues as well as the non-HCC counterpart compared to normal liver tissues. Only few genes were found differentially expressed between HCV-related HCC tissues and paired non-HCC counterpart.</p> <p>Conclusion</p> <p>In this study, informative data on the global gene expression pattern of HCV-related HCC and non-HCC counterpart, as well as on their difference with the one observed in normal liver tissues have been obtained. These results may lead to the identification of specific biomarkers relevant to develop tools for detection, diagnosis, and classification of HCV-related HCC.</p

The role of artificial intelligence in the management of trigeminal neuralgia

Trigeminal neuralgia (TN) is the most frequent facial pain. It is difficult to treat pharmacologically and a significant amount of patients can become drug-resistant requiring surgical intervention. From an etiologically point of view TN can be distinguished in a classic form, usually due to a neurovascular conflict, a secondary form (for example related to multiple sclerosis or a cerebello-pontine angle tumor) and an idiopathic form in which no anatomical cause is identifiable. Despite numerous efforts to treat TN, many patients experience recurrence after multiple operations. This fact reflects our incomplete understanding of TN pathogenesis. Artificial intelligence (AI) uses computer technology to develop systems for extension of human intelligence. In the last few years, it has been a widespread of AI in different areas of medicine to implement diagnostic accuracy, treatment selection and even drug production. The aim of this mini-review is to provide an up to date of the state-of-art of AI applications in TN diagnosis and management

Persistent alveolar air leak following pulmonary lobectomy: an old problem in a modern era

Persistent alveolar air leak (PAAL) after major lung resection remains a common complication in thoracic surgery. The aim of this study was to identify a subset of patients with high risk of developing PAAL after pulmonary lobectomy. Another objective was to evaluate the influence of PAAL on postoperative complications and length of hospital stay. A retrospective analysis on 895 patients undergoing pulmonary lobectomy from January 2014 to December 2019 was performed. PAAL was defined as air leak lasting more than 5 days after lung surgery. Univariate analyses and logistic regressions were performed to identify the predictors of PAAL. A backward selection algorithm was used to identify the optimal set of predictors. The incidence of PAAL was 8.2% (74/895). Male gender (p=0.017), BMI (p<0.001), transient ischemic attack (p=0.031), FEV1 (p=0.018), lobectomy combined with adjacent subsegmentectomy (p=0.018), partial and extended pleural adhesions (p=0.033 and p=0.038, respectively) were identified as independent risk factors for PAAL through logistic regression. A weak positive correlation was found between video-assisted thoracic surgery (VATS) and PAAL following pulmonary lobectomy (p=0.100). PAAL was found to be associated with higher risk of postoperative morbidity (p=0.002) and with longer hospital stay (p<0.001). Both preoperative and intraoperative risk factors may be responsible for PAAL after pulmonary lobectomy. VATS does not appear to prevent this postoperative complication. An alveolar air leak lasting beyond 5 days after pulmonary lobectomy is associated with worse postoperative outcomes.

Clinical significance of prophylactic central compartment neck dissection in the treatment of clinically node-negative papillary thyroid cancer patients

BACKGROUND: Lymph nodal involvement is very common in differentiated thyroid cancer, and in addition, cervical lymph node micrometastases are observed in up to 80 % of papillary thyroid cancers. During the last decades, the role of routine central lymph node dissection (RCLD) in the treatment of papillary thyroid cancer (PTC) has been an object of research, and it is now still controversial. Nevertheless, many scientific societies and referral authors have definitely stated that even if in expert hands, RCLD is not associated to higher morbidity; it should be indicated only in selected cases. MAIN BODY: In order to better analyze the current role of prophylactic neck dissection in the surgical treatment of papillary thyroid cancers, an analysis of the most recent literature data was performed. Prophylactic or therapeutic lymph node dissection, selective, lateral or central lymph node dissection, modified radical neck dissection, and papillary thyroid cancer were used by the authors as keywords performing a PubMed database research. Literature reviews, PTCs large clinical series and the most recent guidelines of different referral endocrine societies, inhering neck dissection for papillary thyroid cancers, were also specifically evaluated. A higher PTC incidence was nowadays reported in differentiated thyroid cancer (DTC) clinical series. In addition, ultrasound guided fine-needle aspiration citology allowed a more precocious diagnosis in the early phases of disease. The role of prophylactic neck dissection in papillary thyroid cancer management remains controversial especially regarding indications, approach, and surgical extension. Even if morbidity rates seem to be similar to those reported after total thyroidectomy alone, RCLD impact on local recurrence and long-term survival is still a matter of research. Nevertheless, only a selective use in high-risk cases is supported by more and more scientific data. CONCLUSIONS: In the last years, higher papillary thyroid cancer incidence and more precocious diagnoses were worldwide reported. Among endocrine and neck surgeons, there is agreement about indications to prophylactic treatment of node-negative “high-risk” patients. A recent trend toward RCLD avoiding radioactive treatment is still debated, but nevertheless, prophylactic dissections in low-risk cases should be avoided. Prospective randomized trials are needed to evaluate the benefits of different approaches and allow to drawn definitive conclusions

Management of Low-Risk Thyroid Cancers: Is Active Surveillance a Valid Option? A Systematic Review of the Literature.

Thyroid cancer is the most common endocrine malignancy, representing 2.9% of all new cancers in the United States. It has an excellent prognosis, with a five-year relative survival rate of 98.3%.Differentiated Thyroid Carcinomas (DTCs) are the most diagnosed thyroid tumors and are characterized by a slow growth rate and indolent course. For years, the only approach to treatment was thyroidectomy. Active surveillance (AS) has recently emerged as an alternative approach; it involves regular observation aimed at recognizing the minority of patients who will clinically progress and would likely benefit from rescue surgery. To better clarify the indications for active surveillance for low-risk thyroid cancers, we reviewed the current management of low-risk DTCs with a systematic search performed according to a PRISMA flowchart in electronic databases (PubMed, Web of Science, Scopus, and EMBASE) for studies published before May 2021. Fourteen publications were included for final analysis, with a total number of 4830 patients under AS. A total of 451/4830 (9.4%) patients experienced an increase in maximum diameter by &gt;3 mm; 609/4830 (12.6%) patients underwent delayed surgery after AS; metastatic spread to cervical lymph nodes was present in 88/4213 (2.1%) patients; 4/3589 (0.1%) patients had metastatic disease outside of cervical lymph nodes. Finally, no subject had a documented mortality due to thyroid cancer during AS. Currently, the American Thyroid Association guidelines do not support AS as the first-line treatment in patients with PMC; however, they consider AS to be an effective alternative, particularly in patients with high surgical risk or poor life expectancy due to comorbid conditions. Thus, AS could be an alternative to immediate surgery for patients with very-low-risk tumors showing no cytologic evidence of aggressive disease, for high-risk surgical candidates, for those with concurrent comorbidities requiring urgent intervention, and for patients with a relatively short life expectancy