Roadmap on thermoelectricity.

The increasing energy demand and the ever more pressing need for clean technologies of energy conversion pose one of the most urgent and complicated issues of our age. Thermoelectricity, namely the direct conversion of waste heat into electricity, is a promising technique based on a long-standing physical phenomenon, which still has not fully developed its potential, mainly due to the low efficiency of the process. In order to improve the thermoelectric performance, a huge effort is being made by physicists, materials scientists and engineers, with the primary aims of better understanding the fundamental issues ruling the improvement of the thermoelectric figure of merit, and finally building the most efficient thermoelectric devices. In this Roadmap an overview is given about the most recent experimental and computational results obtained within the Italian research community on the optimization of composition and morphology of some thermoelectric materials, as well as on the design of thermoelectric and hybrid thermoelectric/photovoltaic devices.

Completely Minimally Invasive Esophagectomy Versus Hybrid Esophagectomy for Esophageal and Gastroesophageal Junctional Cancer: Clinical and Short-Term Oncological Outcomes.

BACKGROUND: Minimally invasive surgery for resectable esophageal and gastroesophageal junctional (GEJ) cancer significantly reduces morbidity when compared with open surgery, as is evident from published landmark trials. Comparison of outcomes between hybrid esophagectomy (HE) and completely minimally invasive esophagectomy (CMIE) remains unclear. OBJECTIVE: We aimed to ascertain whether CMIE is associated with less postoperative complications compared with HE without oncological compromise. METHODS: All consecutive two-stage HEs and CMIEs performed between 2016 and 2018 were included. All procedures were performed with an intrathoracic anastomosis. Primary clinical outcomes were pulmonary infective and overall complications within 30 days of surgery, while primary oncological outcomes included overall survival (OS) and disease-free survival (DFS) at both 6 months and to date. Secondary outcomes included intraoperative variables and postoperative clinical parameters. RESULTS: Overall, 98 patients had CMIEs and 49 patients had HEs. There were no baseline differences between the two groups. Thirty-day postoperative pulmonary infection rates were lower in the CMIE group compared with the HE group (12.2% vs. 28.6%; p = 0.014), and 30-day overall postoperative complication rates were also lower following CMIE (35.7% vs. 59.2%; p = 0.007). OS and DFS were similar between the two groups at 6 months (p = 0.201 and p = 0.109, respectively). CONCLUSIONS: CMIE is associated with less pulmonary infective and overall postoperative complications compared with HE for resectable esophageal and GEJ cancer. No intergroup difference was observed regarding short-term survival and cancer recurrence in patients undergoing CMIE and HE. A randomized controlled trial comparing the two operative approaches is required to validate these findings.

Microvascular grafting to enhance perfusion in colonic long-segment oesophageal reconstruction.

PURPOSE: Oesophagectomy with long-segment colon reconstruction is the first-line treatment when the stomach is not available. Supercharging of the newly formed conduit can improve vascular function utilizing intraoperative perfusion imaging system, following thoracoscopic oesophagectomy for distal-oesophageal and gastroesophageal junction cancer. The purpose of this study is to examine the safety and efficacy of microvascular augmentation of left colonic interposition following oesophagectomy for oesophageal cancer. METHODS: A retrospective analysis of 156 consecutive oesophagectomies between January 2016 and July 2018 was performed. All oesophagectomies involving left colon interposition with microvascular augmentation were included in the study. In all cases, oesophageal mobilization was performed thoracoscopically in prone position and the left colon was used as neo-oesophagus in an isoperistaltic fashion. Conduit perfusion was assessed with the Spy system and neck supercharging was performed using microsurgical technique. RESULTS: A total of n = 5 (3.2%) patients were identified. Two cases had delayed and 3 had immediate reconstruction. The conduit was microsurgically augmented in 3 cases with both venous and arterial anastomoses (supercharging) and in 2 cases with venous anastomosis only (superdrainage). No anastomotic leak was identified. One case developed left recurrent laryngeal nerve palsy with associated aspiration pneumonia. CONCLUSIONS: Supercharged colonic interposition is a safe way of oesophageal reconstruction when long-segment interposition graft is needed. In oesophageal cancer and in the absence of a viable stomach with intact gastroepiploic arcade, it should be considered a feasible option with favourable outcomes, when the expertise and facilities are available. Use of intraoperative perfusion imaging reveals improved conduit blood supply post-supercharging.

Intrathoracic hand-sewn esophagogastric anastomosis in prone position during totally minimally invasive two-stage esophagectomy for esophageal cancer.

Utilization of totally minimally invasive esophagectomy for cancer is on the rise. Esophagogastric anastomosis is mechanically or robotically performed routinely; little report exists of hand-sewn esophagogastric anastomosis. This is the largest so far study with thoracoscopic hand-sewn esophagogastric anastomosis during fully minimally invasive two-stage esophagectomy for esophageal cancer in prone position. Consecutive two-stage totally minimally invasive esophagectomies for cancer were performed by one surgical team, from September 2016 to March 2019. All operations were technically identical in terms of patient positioning, surgical approach, extend of lymphadenectomy and type of anastomosis formed. Primary end points were anastomotic leak and anastomotic stricture rate, while secondary end points were 30-day and 90-day mortality rates. From the overall n = 80 patients, n = 67 were males, while n = 13 were females. Mean age was 64.6 years. Mean length of stay was n = 14 days. There were no conversions to open. Mean operating time was 420 minutes with no blood loss over 200 mL noted. Pulmonary and cardiac complication rate was 23.75% and 2.5%, respectively. Anastomotic leak rate was 2.5%. Anastomotic strictures were seen in 12.5% of cases. 30-day and 90-day mortality rate was 2.5% and 5%, respectively, with none accounted for ischemic conduit complications. Intrathoracic anastomosis in totally minimally invasive esophagectomy is challenging and accountable for most of the mortality associated with the procedure. In thoracoscopic two-stage esophagectomy, a mechanical anastomosis is usually preferred; this is believed to be due to the complexity of manual anastomosis associated with the thoracoscopic approach. We aim to present our series of completely hand-sewn intrathoracic anastomosis utilizing a totally minimally invasive approach with favorable outcomes. With this study, reproducibility of the anastomosis is shown that can potentially favor a change in the practice of esophageal surgeons worldwide.

Self-powered broadband photo-detection and persistent energy generation with junction-free strained Bi2Te3 thin films.

We experimentally demonstrate efficient broadband self-powered photo-detection and power generation in thin films of polycrystalline bismuth telluride (Bi2Te3) semiconductors under inhomogeneous strain. The developed simple, junction-free, lightweight, and flexible photo-detectors are composed of a thin active layer and Ohmic contacts on a flexible plastic substrate, and can operate at room temperature and without application of an external bias voltage. We attribute the observed phenomena to the generation of an electric field due to a spontaneous polarization produced by strain gradient, which can separate both photo-generated and thermally-generated charge carriers in bulk of the semiconductor material, without a semiconductor junction. We show that the developed photo-detectors can generate electric power during both the daytime and the nighttime, by either harnessing solar and thermal radiation or by emitting thermal radiation into the cold sky. To the best of our knowledge, this is the first demonstration of the power generation in a simple junction-free device under negative illumination, which exhibits higher voltage than the previously used expensive commercial HgCdTe photo-diode. Significant improvements in the photo-detector performance are expected if the low-charge-mobility polycrystalline active layer is replaced with high-quality single-crystal material. The technology is not limited to Bi2Te3 as the active material, and offers many potential applications in night vision, wearable sensors, long-range LIDAR, and daytime/nighttime energy generation technologies.

Thoracoscopic total esophagogastrectomy with supercharged colon interposition for the treatment of esophageal adenocarcinoma in situs inversus.

Background: Esophagectomy in situs inversus is challenging. With long-segment supercharged reconstruction, it becomes more perplexing and multidisciplinary surgical skills are needed. Challenges met and the surgical technique used is presented in this case report. Methods: The case of a 49-year old patient with situs inversus abdominus and a locally advanced distal esophageal adenocarcinoma extending to the stomach is presented. Results: Following neoadjuvant chemotherapy and due to inability to use the stomach as a conduit, a thoracoscopic total esophagogastrectomy with long-segment reconstruction was performed. The conduit used was the left colon and was supercharged with venous and arterial anastomoses in the neck. Conduit perfusion, as assessed by the Spy system revealed marked improvement post supercharging. No anastomotic leak was noted and oral diet was started on day 4. On day 26 the patient developed pneumonia necessitating intubation that was declined. Organ support was withheld with patient death at day 29. Conclusion: In long-segment esophageal reconstruction with supercharged colon, although thoracoscopy is feasible, laparoscopy is found unsafe. Careful preoperative planning and colon assessment via computed tomography(CT) colonography/angiography and a multidisciplinary team approach is recommended. Adjuncts to assess conduit perfusion like the Spy system are helpful. Supercharging the long colonic conduit is a way of minimizing ischemia-related complications.

Transmural migration of azygous vein Hem-O-lok clip causing food bolus 3 months following uneventful minimally invasive oesophagectomy.

BACKGROUND: Hem-o-lok clips are widely deployed in various laparoscopic and robotic operations. Their migration is not very common and majority of reported cases are limited to biliary, prostatic and vesico-urethral cases. METHODS: Herein, we would like to report the first case of transmural migration of Hem-o-lok clip from azygous vein stump following totally minimally invasive two-stage oesophagectomy for squamous cell carcinoma of the distal oesophagus, into the gastric conduit 3-months following uneventful discharge. The patient presented with 5-days history of worsening dysphagia. RESULTS: The subsequent gastroscopy revealed normal gastric conduit with two Hem-o-lok clips containing the azygous vein stump within its lumen at the level of the oesophago-gastric anastomosis, propagating a food bolus obstruction. The foreign body was successfully removed and the patient was discharged the same day without any complications at 5 months follow up. CONCLUSION: Hem-o-lok clip migration trends to be a well-established event. However, their mechanism and exact incidence remains elusive to this date. To the best of our knowledge, their migration in oesophageal cancer surgery has not been reported.

Gastric conduit obstruction due to gastroduodenal compression: a new complication post-Ivor-Lewis oesophagectomy.

INTRODUCTION: Oesophagectomy for oesophageal carcinoma carries a high risk of significant morbidity and mortality. Delayed gastric emptying is a relatively common complication following this procedure. A variety of medical, surgical and endoscopic strategies have been described to manage it. The vast majority of cases are related to post-operative pyloric dysfunction and are amenable to conventional management strategies. PATIENTS AND METHODS: We present a new case of a patient with a duodenal hiatus hernia resulting in extrinsic gastroduodenal compression by the massively distended gastric conduit as a cause of gastric outlet obstruction following laparoscopic-assisted Ivor-Lewis oesophagectomy 2 years previously. RESULTS AND CONCLUSIONS: Surgical repair of the hiatus hernia restored the post-oesophagectomy anatomy and resolved this patient's symptoms where conventional management of post-oesophagectomy gastric outlet obstruction had failed on multiple occasions. Most cases of delayed gastric emptying post-oesophagectomy occur as a result of pyloric dysfunction and can be managed using a combination of prokinetics, surgical intervention or more commonly, endoscopic dilatation. Other potential causes and therefore investigative and management strategies should be considered in patients who repeatedly fail conventional management. We offer an alternative diagnosis that may be considered in these patients and present a novel approach to their investigation and management.

Theoretical Analysis of Two Novel Hybrid Thermoelectric-Photovoltaic Systems Based on Cu2ZnSnS4 Solar Cells.

The development and commercialization of Photovoltaic (PV) cells with good cost-efficiency trade-off not using critical raw materials (CRMs) is one of the strategies chosen by the European Community (EC) to address the Energy Roadmap 2050. In this context Cu2ZnSnS4 (CZTS) solar cells are attracting a major interest since they have the potential to combine low price with relatively high conversion efficiencies. Although a ≈9% lab scale efficiency has already been reported for CZTS this technology is still far from being competitive in terms of cost per peak-power (€/Wp) with other common materials. One possible near-future solution to increase the CZTS competiveness comes from thermoelectrics. Actually it has already been shown that Hybrid Thermoelectric-Photovoltaic Systems (HTEPVs) based on CIGS, another kesterite very similar to CZTS, can lead to a significant efficiency improvement. However it has been also clarified how the optimal hybridization strategy cannot come from the simple coupling of solar cells with commercial TEGs, but special layouts have to be implemented. Furthermore, since solar cell performances are well known to decrease with temperature, thermal decoupling strategies of the PV and TEG sections have to be taken. To address these issues, we developed a model for two different HTEPV solutions, both coupled with CZTS solar cells. In the first case we considered a Thermally-Coupled HTEPV device (TC-HTEPV) in which the TEG is placed underneath the solar cell and in thermal contact with it. The second system consists instead of an Optically-Coupled but thermally decoupled device (OC-HTEPV) in which part of the solar spectrum is focused by a non-imaging optical concentrator on the TEG hot side. For both solutions the model returns conversion efficiencies higher than that of the CZTS solar cell alone. Specifically, increases of ≈30% are predicted for both kind of systems considered.

Role of 3D in minimally invasive esophagectomy.

PURPOSE: Two-stage minimally invasive esophagectomy (MIE) has gained popularity in the surgical treatment of esophageal cancer. MIE's limitation is embedded in the construction of intrathoracic anastomosis. Various anastomotic techniques have been reported; however, the mechanical one remains the most commonly adopted. This pilot study aims to describe an efficient, safe, and reproducible way of performing a hand-sewn intrathoracic esophagogastric anastomosis in conjunction with short-term results using 2D and 3D thoracoscopic approaches. METHODS: A total of n = 13 patients (mean age 67.4) underwent MIE for distal esophageal or gastroesophageal junction adenocarcinoma between January and September 2016. Resection was performed in prone position, and the esophagogastric anastomosis was constructed in an end-to-side manner in two layers with barbed knotless suture. A 2D thoracoscopic approach was used in n = 10 patients (77%) and a 3D approach in n = 3 (23%). RESULTS: n = 8 patients (61.5%) had neo-adjuvant chemotherapy and n = 5 (38.5%) had primary surgery. The mean operating time was 420 min, and the average length of stay was 10 days with no associated mortality. n = 1 (7.7%) developed a radiological leak that did not require an intervention. Thoracoscopic approach with the glasses-based 3D optical system using the angulating-tip 100° camera provided a far superior view for precise lymphadenectomy in combination to an efficient and safe construction of the anastomosis. CONCLUSION: The barbed knotless suturing technique in MIE is an efficient and safe method of constructing the esophagogastric anastomosis with promising short-term outcomes. A 3D thoracoscopic approach appears to be superior in performing the anastomosis to that of a 2D technique.

Interstitial cells of Cajal modulate the tone of the human internal anal sphincter in vitro.

BACKGROUND: Interstitial cells of Cajal, expressing the proto-oncogene c-kit, have been shown to regulate the spontaneous activity of the gastrointestinal tract. They have been described in the human internal anal sphincter; however, their function is still unclear. OBJECTIVE: We examined the effects of the c-kit tyrosine kinase inhibitor imatinib mesylate on sphincter strips to investigate the function of the interstitial cells. DESIGN: This was a case series study. SETTIGS: This was a single-center study conducted at the University of Oxford. PATIENTS: Internal anal sphincter strips were collected from 10 patients undergoing abdominoperineal resection or proctectomy and mounted in organ bath. Responses to electrical field stimulation and chemical agents were monitored in the absence of drugs and after the administration of increasing doses of imatinib mesylate. Immunohistochemistry was performed to identify interstitial cells. MAIN OUTCOME MEASURES: The role of the interstitial cells in the internal anal sphincter was assessed. RESULTS: Imatinib mesylate significantly reduced the tone and the spontaneous activity of the strips. In the absence of drugs, the tone generated was 147.7 ± 33.0 mg/mg of tissue. Administration of ≥5 µM of imatinib mesylate caused a dose-dependent reduction in the tone. Strips exhibited spontaneous activity characterized by intermittent low-amplitude contractions superimposed on basal tone (135.6 ± 4.6 contractions in 10 minutes). Imatinib mesylate significantly reduced the number of contractions at concentration >5 µM. No differences were observed in the responses to electrical field stimulation, carbachol, or phenylephrine. Immunohistochemistry showed c-kit-positive cells. LIMITATIONS: This study was limited by the relatively small number of patients enrolled and thus the difficulty of finding human tissue for laboratory studies. CONCLUSIONS: Our results suggest that the interstitial cells modulate the tone and the spontaneous activity of the internal anal sphincter. This provides a foundation for new approaches to preclinical and clinical research. Moreover, these cells may represent a target for drugs inhibiting the c-kit receptor and provide a new approach for treating anorectal diseases.

Prognostic factors for primary gastrointestinal stromal tumours: are they the same in the multidisciplinary treatment era?

PURPOSE: Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumour of the gastrointestinal tract. The introduction of tyrosine kinase inhibitors (TKIs) has lead to increasing use of combination of medical and surgical therapy. The aim of this study was to look at outcomes from a series of surgically treated GISTs and determine prognostic factors in the context of multimodal therapy. METHODS: We analysed 104 single surgeon's patients with GIST. End points of the study were disease-specific survival (DSS), disease-free survival (DFS) and post-operative complications. RESULTS: Three- and 5-year DSS rates were 96.7 and 94.6 %. On univariate analysis, clear resection margins were predictive of DSS. Patients with R2 resection had a worse prognosis (3-year DSS rate of 83.3 %; 5-year DSS rate of 62.5 %) compared to patients with R0 (3-year DSS rate of 98 %; 5-year DSS rate of 98 %) or R1 resection (3-year DSS rate of 100 %; 5-year DSS rate of 100 %) (R0 vs R1 vs. R2 p = 0.001). Pre-operative factors associated with R2 resection were clinical metastatic disease (p < 0.001), non-gastric tumour site (p = 0.002) and large tumour diameter (p = 0.031). Three- and 5-year DFS rates were 65.5 and 59.8 %. Serosal perforation (p = 0.013) and mitotic rate (p = 0.05) were found to be independently predictive of increased DFS. The presence of serosal perforation was associated with tumour site (p = 0.018), mitotic rate (p = 0.035), tumour diameter (p < 0.001), growth pattern (p = 0.007) and age (p = 0.040). CONCLUSIONS: In the multidisciplinary management of GIST, serosal perforation may represent an additional predictor of recurrence along with mitotic rate. Complete macroscopic surgical resection is the most reliable prognostic factor, and an aggressive surgical approach should be advocated.

"Chronic" metastatic pancreatic acinar cell carcinoma.

Acinar cell carcinoma (ACC) of the pancreas is a rare exocrine tumour for which there is very limited information about chemotherapy regimens and prognosis. Even though there are clinical guidelines for management of ductal cell carcinoma, a definitive and specific regime has not yet been agreed for this type of pancreatic cancer. We report a case of metastatic ACC of pancreas who has been treated with a multimodal approach, including novel combinations of different targeted drugs with conventional chemotherapy, surgery and radiofrequency ablation since the last 11 years. This degree of long term survival has not been reported so far in such a case of metastatic ACC of the pancreas. This case highlights the importance of a personalised multidisciplinary therapeutic strategy, employing locoregional therapies along with combinations of established and novel systemic therapies to control the disease, and the importance of flexibility when instigating new treatment paradigms for progressive cancer. Also, this case demonstrates that complete tumour eradication may not be the sole purpose of surgical oncology.

Simultaneous increase in electrical conductivity and Seebeck coefficient in highly boron-doped nanocrystalline Si.

A large thermoelectric power factor in heavily boron-doped p-type nanograined Si with grain sizes ∼30 nm and grain boundary regions of ∼2 nm is reported. The reported power factor is ∼5 times higher than in bulk Si. It originates from the surprising observation that for a specific range of carrier concentrations, the electrical conductivity and Seebeck coefficient increase simultaneously. The two essential ingredients for this observation are nanocrystallinity and extremely high boron doping levels. This experimental finding is interpreted within a theoretical model that considers both electron and phonon transport within the semiclassical Boltzmann approach. It is shown that transport takes place through two phases so that high conductivity is achieved in the grains, and high Seebeck coefficient by the grain boundaries. This together with the drastic reduction in the thermal conductivity due to boundary scattering could lead to a significant increase of the figure of merit ZT. This is one of the rare observations of a simultaneous increase in the electrical conductivity and Seebeck coefficient, resulting in enhanced thermoelectric power factor.

Short-term effects of neoadjuvant chemoradiotherapy on internal anal sphincter function: a human in vitro study.

BACKGROUND: Neoadjuvant chemoradiotherapy is recommended in the treatment of locally advanced rectal cancer. Studies have suggested that chemoradiotherapy adversely affects anorectal function. However, the functional implication and the underlying neuromyogenic changes involved in radiation-induced damage are poorly understood. OBJECTIVE: This study evaluated the functional changes following chemoradiotherapy on the internal anal sphincter. DESIGN AND PATIENTS: This article describes an in vitro study on the internal anal sphincter collected from patients undergoing abdominoperineal resection or proctectomy. Five patients were treated by surgery alone (control group), and 6 received preoperative chemoradiotherapy (treatment group). Sphincter strips were mounted in organ bath, and the responses to electrical field stimulation and drugs were monitored. SETTINGS: The study was performed at the University of Oxford. MAIN OUTCOME MEASURES: The end points of this study were to investigate whether chemoradiotherapy has any significant effects on internal anal sphincter function and, subsequently, to establish the type of injury induced. RESULTS: Chemoradiotherapy strips developed similar tone, but significantly lower spontaneous activity (p = 0.001) than controls. Electrical field stimulation induced relaxation, followed by contraction. At 50 Hz, electrical field stimulation produced 25.6 ± 4.9% (mean ± SE) of maximum relaxation followed by a contraction of 5.5 ± 0.9% of basal tone in chemoradiotherapy strips i9n comparison with 47.0 ± 6.2% (p = 0.009) and 17.7 ± 4.0% (p = 0.007) in controls. Relaxation was significantly attenuated by N-nitro-L-arginine. Significant differences were found in responses to carbachol (p = 0.018) and phenylephrine (p = 0.022), but not to sodium nitroprusside. LIMITATIONS: This work was limited by the relatively small number of patients enrolled, because of the difficulty of finding human tissue for laboratory studies, and the lack of long-term results. CONCLUSIONS: Chemoradiotherapy significantly impairs internal anal sphincter function and intrinsic nerves seem more susceptible than smooth muscle. The exclusion of anal canal from the radiation field is recommended, when oncologically safe.

Laparoscopic-assisted endoscopic sigmoidopexy: a new surgical option for sigmoid volvulus.

OBJECTIVES: Sigmoid volvulus accounts for 5% of cases of large-bowel obstruction. Here, we present the development of a new minimally invasive treatment method that aims to reduce the complication rate of standard percutaneous endoscopic colostomy tube insertion and negate the need for prolonged anesthesia or colectomy. METHODS: Six patients underwent laparoscopic-assisted endoscopic sigmoidopexy for recurrent sigmoid volvulus at a mean age of 80.5 years (range, 76-83). The volvulus was decompressed endoscopically before laparoscopic adhesiolysis and detorsion of the sigmoid. Finally, the sigmoid was approximated with the anterior abdominal wall, and 2 endoscopically placed percutaneous endoscopic colostomy tubes were inserted. Later, the external component of the percutaneous endoscopic colostomy tubes was removed, and the internal parts were passed by way of the rectum. RESULTS: Each operation was completed successfully in a mean time of 69 minutes and with no intraoperative complication. The mean postoperative stay was 20 days (range, 4-54). At median follow-up of 10.8 months, all patients were tube free with no incidence of recurrent volvulus, inadvertent tube traction, or leak. CONCLUSIONS: This preliminary report shows laparoscopic-assisted endoscopic sigmoidopexy to be a safe treatment modality for recurrent sigmoid volvulus. As such, it is particularly useful for elderly patients, for whom colectomy is a high-risk procedure.

Economic Convenience of Hybrid Thermoelectric-Photovoltaic Solar Harvesters.

Over the last few years, a growing interest has surfaced about the possibility of enhancing solar harvester efficiency by coupling photovoltaic (PV) cells with thermoelectric generators (TEGs). To be effective solutions, hybrid thermoelectric-photovoltaic (HTEPV) solar harvesters must not only increase the solar conversion efficiency but should also be economically competitive. The aim of this paper is to estimate the profitability of HTEPV solar harvesters with no reference to specific materials, relating it instead to their physical properties only and thus providing a tool to address research effort toward classes of HTEPV systems able to compete with current PV technologies. An economic convenience index is defined and used to assess the economic sustainability of hybridization. It is found that, although hybridization often leads to enhanced solar power conversion, power costs (USD/W) may not always justify HTEPV deployment at the current stage of technology. An analysis of the cost structure shows that profitability requires largely enhanced thermoelectric stages, concentrated solar cells, or PV materials with favorable temperature efficiency coefficients, such as perovskite solar cells.

All-Oxide p-n Junction Thermoelectric Generator Based on SnOx and ZnO Thin Films.

Achieving thermoelectric devices with high performance based on low-cost and nontoxic materials is extremely challenging. Moreover, as we move toward an Internet-of-Things society, a miniaturized local power source such as a thermoelectric generator (TEG) is desired to power increasing numbers of wireless sensors. Therefore, in this work, an all-oxide p-n junction TEG composed of low-cost, abundant, and nontoxic materials, such as n-type ZnO and p-type SnOx thin films, deposited on borosilicate glass substrate is proposed. A type II heterojunction between SnOx and ZnO films was predicted by density functional theory (DFT) calculations and confirmed experimentally by X-ray photoelectron spectroscopy (XPS). Moreover, scanning transmission electron microscopy (STEM) combined with energy-dispersive X-ray spectroscopy (EDS) show a sharp interface between the SnOx and ZnO layers, confirming the high quality of the p-n junction even after annealing at 523 K. ZnO and SnOx thin films exhibit Seebeck coefficients (α) of ∼121 and ∼258 µV/K, respectively, at 298 K, resulting in power factors (PF) of 180 µW/m K2 (for ZnO) and 37 µW/m K2 (for SnOx). Moreover, the thermal conductivities of ZnO and SnOx films are 8.7 and 1.24 W/m K, respectively, at 298 K, with no significant changes until 575 K. The four pairs all-oxide TEG generated a maximum power output (Pout) of 1.8 nW (≈126 µW/cm2) at a temperature difference of 160 K. The output voltage (Vout) and output current (Iout) at the maximum power output of the TEG are 124 mV and 0.0146 µA, respectively. This work paves the way for achieving a high-performance TEG device based on oxide thin films.

Thymidine phosphorylase expression in metastatic sites is predictive for response in patients with colorectal cancer treated with continuous oral capecitabine and biweekly oxaliplatin.

The primary objective of this study was to determine the activity and safety profile of biweekly oxaliplatin combined with continuous oral capecitabine in the first-line treatment of metastatic colorectal cancer. A secondary endpoint was to investigate the correlation between thymidylate synthase and thymidine phosphorylase (TP) expression in metastatic tissues and tumor response. Forty-one patients received oral capecitabine 1331 mg/m every day combined with intravenous oxaliplatin 85 mg/m every 2 weeks. The overall response rate was 58.5% [95% confidence interval (CI): 43.3-73.6%], the median progression-free survival 9.4 months (95% CI: 7.7-11.2 months) and the median survival 22.3 months (95% CI: 16.1-27.5 months). There were no grade 4 toxicities, and grade 3 toxicity was also uncommon. High TP expression in metastatic tissue was significantly associated with response to treatment (P=0.019), and also with a trend towards a better median progression-free survival and overall survival compared with patients expressing low TP (P=0.056; P=0.073). This study suggests that biweekly oxaliplatin and continuous oral capecitabine is an active and well-tolerated chemotherapy regimen in the first-line treatment of metastatic colorectal cancer. Moreover, these findings add to a growing body of evidence that patients with high levels of intratumoral TP expression are the ideal candidates for capecitabine-based chemotherapy.

Hybrid Minimally-invasive Esophagectomy for Esophageal Cancer: Clinical and Oncological Outcomes.

BACKGROUND/AIM: Esophagectomy is a major surgical procedure associated with a significant risk of morbidity and mortality that has traditionally been performed by an open approach. Although minimally invasive procedures for benign esophageal disease have been widely accepted worldwide, they have not yet been established for the treatment of malignancy. PATIENTS AND METHODS: A total of 137 consecutive hybrid esophagectomies for cancer were performed by the same surgical team. Surgical approach included either 2-stage or 3-stage hybrid minimally-invasive esophagectomy. RESULTS: Median age of patients was 64 years. Respiratory complication and anastomotic leak rates were 16.78% and 9.48%, respectively. Median follow-up was 48 months with median overall survival and disease free survival were 58 and 48 months, respectively. CONCLUSION: Advances in minimally invasive surgery can benefit patients with esophageal cancer, mainly by reducing post-operative respiratory complications. Hybrid esophagectomy is safe and feasible in tertiary esophago-gastric centers with vast expertise that can lead to improved clinical and oncological outcomes.