Tailoring single-mode random lasing of tin halide perovskites integrated in a vertical cavity

The development of random lasing (RL) with predictable and controlled properties is an important step to make these cheap optical sources stable and reliable. However, the design of tailored RL characteristics (emission energy, threshold, number of modes) has been only obtained with complex photonic structures, while the simplest optical configurations able to tune the RL is still a challenge. This work demonstrates the tuning of the RL characteristics in spin-coated and inkjet-printed tin-based perovskites integrated into a vertical cavity with low quality factor. When the cavity mode is resonant with the photoluminescence (PL) peak energy, standard vertical lasing is observed. More important, single mode RL operation with the lowest threshold and a quality factor as high as 1000 (twenty times the quality factor of the resonator) is obtained if the cavity mode lies above the PL peak energy due to higher gain. These results can have important technological implications towards the development of low-cost RL sources without chaotic behavior. This article is protected by copyright. All rights reserved.

Large-Area, Flexible, Lead-Free Sn-Perovskite Solar Modules

For the first time, large-area, flexible organic-inorganic tin perovskite solar modules are fabricated by means of an industry-compatible and scalable blade-coating technique. An 8-cell interconnected mini module with dimensions of 25 cm2 (active area = 8 × 1.5 cm2) reached 5.7% power conversion efficiency under 1000 W/m2 (AM 1.5G) and 9.4% under 2000 lx (white-LED).

Inkjet-printed h-BN memristors for hardware security

Inkjet printing electronics is a growing market that reached 7.8 billion USD in 2020 and that is expected to grow to ∼23 billion USD by 2026, driven by applications like displays, photovoltaics, lighting, and radiofrequency identification. Incorporating two-dimensional (2D) materials into this technology could further enhance the properties of the existing devices and/or circuits, as well as enable the development of new concept applications. Along these lines, here we report an easy and cheap process to synthesize inks made of multilayer hexagonal boron nitride (h-BN)-an insulating 2D layered material-by the liquid-phase exfoliation method and use them to fabricate memristors. The devices exhibit multiple stochastic phenomena that are very attractive for use as entropy sources in electronic circuits for data encryption (physical unclonable functions [PUFs], true random number generators [TRNGs]), such as: (i) a very disperse initial resistance and dielectric breakdown voltage, (ii) volatile unipolar and non-volatile bipolar resistive switching (RS) with a high cycle-to-cycle variability of the state resistances, and (iii) random telegraph noise (RTN) current fluctuations. The clue for the observation of these stochastic phenomena resides on the unpredictable nature of the device structure derived from the inkjet printing process (i.e., thickness fluctuations, random flake orientations), which allows fabricating electronic devices with different electronic properties. The easy-to-make and cheap memristors here developed are ideal to encrypt the information produced by multiple types of objects and/or products, and the versatility of the inkjet printing method, which allows effortless deposition on any substrate, makes our devices especially attractive for flexible and wearable devices within the internet-of-things.

2D PEA2SnI4 Inkjet-Printed Halide Perovskite LEDs on Rigid and Flexible Substrates

Lead-free PEA₂SnI₄-based perovskite LEDs are successfully inkjet-printed on rigid and flexible substrates. Red-emitting devices (λ_max = 633 nm) exhibit, under ambient conditions, a maximum external quantum efficiency (EQE_max) of 1% with a related brightness of 30 cd/m² at 10 mA/cm².

Low-Power, High-Performance, Non-volatile Inkjet-Printed HfO2-Based Resistive Random Access Memory: From Device to Nanoscale Characterization

Low-power, high-performance metal-insulator-metal (MIM) non-volatile resistive memories based on HfO₂ high- k dielectric are fabricated using a drop-on-demand inkjet printing technique as a low-cost and eco-friendly method. The characteristics of resistive switching of Pt (bottom)/HfO₂/Ag (top) stacks on Si/SiO₂ substrates are investigated in order to study the bottom electrode's interaction with the HfO₂ dielectric layer and the resulting effects on resistive switching. The devices show low Set and Reset voltages, high ON/OFF current ratio, and relatively low switching current (∼1 μA), which are comparable to the characteristics of current commercial CMOS memories. In order to understand the resistive switching mechanism, direct structural observation is carried out by field-emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HRTEM) on cross-sectioned samples prepared by focused ion beam (FIB). In addition, electron energy loss spectroscopy (EELS) inspections discard a silver electro-migration effect.

[Hurthle cell neoplasm: our experience]

Hurthle cell neoplasm is a rare form of thyroid tumors, comprising from 1.5% to 10% of all tumors. Hurthle cell nodules are clinically indistinguishable from other nodular thyroid diseases. The histologic features of Hurthle cell neoplasm don't allow us to exactly distinguish benign nodules from malignant ones. Accurate histologic valutation is possible and necessary for a correct diagnosis and therapy of Hurthle cell tumors. The adenomas usually exhibit a follicular pattern; the carcinomas include a subset of Hurthle cell tumors with different biological behavior, including malignant follicular variants and papillary ones. The authors are in favour of total thyroidectomy for carcinomas and lobectomy plus isthectomy for adenomas; in case of carcinomas, the lymphadenectomy reduces the incidence of local relapse and is necessary in case of lymphnode involvement. Adjuvant radiation therapy is successful in preventing recurrences, in symptomatic metastates as palliative therapy and control recurrence of advanced resected tumors.

[Non derivated surgery indications and limits in bile duct iatrogenic injuries treatment]

Recently the incidence of iatrogenic bile duct injuries has increased proportionally to development of the laparoscopic surgery. The objective of this study is to determine the possible application of non derivated surgical repairs in iatrogenic bile duct injuries treatment of the above procedures. These surgical approaches range from simply placing a surgical drainage to liver transplantation. With reference to Strasberg's classification non derivated treatments are listed, furthermore are discussed and analysed their indications and limits. Owing to their experience and specific literature, the authors came to the following conclusions: 1) These surgical options represent an ideal reconstruction technique because they restore bile ducts continuity without altering physiological mechanisms to which these anatomical structures are appointed. 2) The indications of applying these methods are rare and usually limited to those cases in which the lesion has been recognized during operation and in the immediate post operative period.

[Functional results of colorectal and coloanal anastomosis with and without pouch]

In the last two decades one of the main targets of anorectocolonic surgery has been to develop sphincter saving procedure able to achieve good results with acceptable five-years survivals, optimal local control of the diseases and low rate of local cancer recurrence. Partially the development of new operative techniques such as low colorectal and coloanal anastomoses with or without pouch, the TME operation and the nerve sparing procedure have reach this target. In fact, often after these operations we can observe a functional syndrome called "Post Anterior Resection Syndrome". The basis of this syndrome have to researched in anatomical and physiological alterations that followed a reconstructive operation. It is characterized by frequency and fragmentation of the stool, feeling of incomplete evacuation, tenesmus and urgency. Fecal continence may be compromised to different levels: usually with alteration limited to soiling and impaired control of flatus, occasionally with loss of liquid stool, rarely with loss of solid stools. The anorectal function will be altered for long time following the surgical procedure and the stabilization of functional results may require 1-3 years. On the basis of these considerations, the authors examine the etiopathogenesis and clinical presentation of the "Post Anterior Resection Syndrome", suggesting some expedients to prevent the functional problems. Analysing our experience and a wide specific bibliography, they also underline the indispensable point to achieve a good functional results after a reconstructive procedure. The author conclude asserting that the absence of these points have to be carefully valued because, in these situations, a simply colostomy is able to guarantee a better quality of life that a colorectal/coloanal anastomoses with or without pouch but associated to functional problems.

[Fournier syndrome: multidisciplinary approach]

Fournier's gangrene, a form of necrotizing fasciitis, is an uncommon, fulminant, rapidly progressing subcutaneous infection of the scrotum and genito-perineal region, and may occur in all age groups. Most cases involve a mixed synergistic infection of aerobic and anaerobic bacteria, and occur as a result of one of this mechanisms: local trauma, extension from a perineal, periurethral or ischiorectal infection. It is associated with a high mortality rate. Predisposing factors included diabetes mellitus, steroids or chemotherapy, alcohol abuse, malignancy and radiation therapy. This disease requires prompt treatment: early diagnosis, antibiotic therapy, nutritional support, immediate extensive surgical debridement and hyperbaric oxygen therapy. The use of etherologue serum is a valuable adjunct in the therapy of Fournier's gangrene. We report a case of Fournier's syndrome treated with etherologue serum immuno-therapy, together with the conventional multidisciplinary approach. The postoperative course was uneventful and the patient was discharged on day 50 post intervention in good general conditions. The 3 years follow-up showed no recurrence of the disease. In conclusion we remark that the survival can be improved in patients with Fournier's gangrene by multidisciplinary approach.

[Extended total gastrectomy: indications in the 3rd millennium]

BACKGROUND

Total extended gastrectomy (TEG) is indicated in the treatment of gastric cancer for necessity or to achieve an oncologic radicality. By this surgical treatment the stomach and other organs or a part of them involved by primitive tumor are removed.

METHODS

The authors report a study about 15 patients, out of 116 cases of gastric cancer, operated by TEG between 1990-1998. The middle-age of this patients was 63 years (range 45-76) and their general conditions were good in 9 cases and not-good in 6. The postoperative total parenteral nutrition (TPN) was carried out in all the patients, while preoperatively only in the most compromised patients. The surgical treatments were: 2 TG (total gastrectomy)+splenecomy; 3 TG+splenectomy+pancreatic resection; 4 TG+splenectomy+pancreatic resection+distal esophageal resection; 1 TG+distal esophageal resection; 2 TG+atypic hepatic resection; 1 TG+ atypic hepatic resection+duodenum resection; 2 TG+large intestine resection. While 10 patients were operated on to obtain radicality, 5 patients had a palliative treatment.

RESULTS

There was not perioperative mortality, but we have observed: one dehiscence of the duodenal stump and one pancreatic fistula treated with conservative therapy; one left subfrenic abscess treated with surgical therapy. The survival has been higher in the patients treated with radicality. On the basis of these cases, the authors consider: 1) the possibility to obtain radicality by TEG; 2) the gastric localizations more often associated to extravisceral neoplastic localization; 3) the role of extensive lymph node resection (III and IV level) to obtain oncological radicality or neoplastic reduction. CONCLUSIONS. On the basis of their personal experience and related literature, the authors conclude that TEG is indicated to: 1) obtain a better lymphadenectomy; 2) obtain an oncologic radicality; 3) reduce the neoplastic mass in order to facilitate adjuvant therapy; 4) avoid or treat neoplastic complications; 5) improve the quality of life.

Madelung's disease: case report and discussion of treatment options

Madelung's disease was first described in 1846. Since then, approximately 200 patients have been reported in the literature. Its three main characteristics-typical location of the lesions, symmetry, and the diffusive nature of the fat-are more often found in men of Mediterranean descent. A clear association with alcohol abuse is reported, but the etiology remains uncertain. Patients usually complain of their cosmetic appearance, but treatment can be rendered for decreased neck motion and/or aerodigestive problems. Given the benign nature of the lesion, surgical debulking is the treatment of choice, with liposuction reserved for smaller lesions. A standard facelift pattern can be used for skin incisions and removal, with good cosmetic results.

[Complicated Spigelian hernia: our experience]

We present a case of complicated Spigelian hernia presented with symptoms of intestinal occlusion, in a 50 years old woman. Spigelian hernia represents 1-2% of all abdominal hernias and can occur anywhere along the semicircular line of Douglas. The patient underwent emergency surgery followed by polypropylene plastic repair. The postoperative course was uneventful and the patient was discharged on day 8 post intervention in good general conditions. The 2 years follow-up showed no recurrence of the disease. Clinical examination is the foundation of the diagnosis, whereas radiological findings (ultrasonography, TC) allow the exclusion of other pathologies in the differential diagnosis. The preoperative diagnosis is difficult, mainly because of the non-specificity of symptoms as well as the few cases reported in the literature. In conclusion, we remark that the surgery remains the most effective treatment of Spigelian Hernia.

[Zenker's diverticulum. Apropos a case]

The authors report a case of Zenker's diverticulum in a patient 72 years old who underwent surgery. The pharyngoesophageal function was investigated before and after cricopharyngeal myotomy and diverticulopexy, with oesophageal manometry. Preoperative manometry showed an incomplete relaxation of the upper oesophageal sphincter and increased of pharyngeal pressure. This diverticulum has a pulsion pathogenesis and in this case is not associated with gastroesophageal reflux. It is important to check whether an associated oesophageal pathology exist once Zenker's diverticulum has been diagnosed: X-ray examination of oesophagus and stomach are capable of identifying the presence of diverticulum as well as other pathological association. In the case showed the clinical manifestation are represented by: cervical dysphagia, sensation of foreign body while eating due to the accumulation of ingested food in the diverticulum, and noisy deglutition. The surgical treatment in this case consist of diverticulopexy with cricopharyngeal myotomy. This case is treated with diverticulopexy for two reason: because is not very big and to reduce post-operative period. In conclusion the authors shows the importance of this surgery for not very large sized pouches, and emphasise the importance of manometric and radiographic control in pre and post-operative period. This kind of surgery reduce post-operative complication and the period to stay in bed.

[Morgagni-Larrey diaphragmatic hernia: report of a case]

The Authors presents a Morgagni-Larrey's diaphragmatic hernia case, observed during subocclusive manifestation. They emphasize the utility to perform always the surgical intervention, also in the asintomatic cases.

[Meigs' syndrome: its clinical picture and treatment]

Meigs' syndrome is a rare clinical entity characterised with ovarian benign tumour, ascites and hydrothorax. Between January '94-September '98 we observed three patients with: ovarian neoformation, light (1 patient), moderate (2 patients) monolateral pleural effusion, moderate (2 patients) and considerable (1 patient) ascites. In all patients the preoperative evaluation (sero-haematologic routine, Ca 125 and other oncologic markers, chest X-ray, abdominal and pelvic ultrasonography, total-body Tc, cytological analysis of pleural and abdominal effusion) was suggestive for malignancy but not confirmed it. So an explorative laparotomy with histological extemporary analysis was performed. The results were: 1 fibrothecomas, 1 fibroma, 1 ovarian inflammation with cystic luteinization areas and fibromatosis uterine. All three patients had a good postoperative course. The symptomatology and the effusions disappeared 7-10 days after operation. The first two cases were diagnosed as classic Meigs' syndrome, the third one, instead, as a pseudo-Meigs's syndrome. In conclusion the A.A., according to literature and their experiences, underline: 1) an ovarian mass with pleural and abdominal effusion not always represents an advanced malignancy; 2) even if elevated Ca 125 value is usually associated to a ovarian malignancy, there are some benign lesions in which we observed elevated level of this marker 3) the removal of the ovarian mass is the only resolutive treatment for these patients.

[Rare primary localization of echinococcus cysts. Presentation of 2 cases and review of the literature]

Hydatidosis is a parasitic disease. It's generally localized in the liver and in the lung even if any other organ can be potentially affected. From 92 to 98 our group observed two cases of rare primitive localisation of echinococcosis (one mediastinal and one retroperitoneal cyst). The patients performed serologic and instrumental exams to establish the right therapeutic strategy. Both of them were operated (it was carried out a pericystectomy with open cyst in one of them and an exeresis of the right adrenal gland including hydatid cyst in the other one). A patient underwent to Albendazole prophylaxis. During the follow-up the patients performed echography, CT and MRI. Considering the literature's data and their experience the authors emphasize: 1. The diagnosis of rare primitive localization of hydatidosis is very difficult. 2. The diagnostic iter requires a correct relationship between the laboratory and imaging data. 3. Only the exclusion of other localizations of the cyst (liver, lung or other organs) give us the possibility to diagnose a rare primitive localization of hydatidosis. 4. The treatment of hydatidosis is specifically surgical. 5. The surgeon can use several different approaches in relationship to the place and the anatomopathologic characters of the cyst.

[Routine broncho-myo-plasty after pneumonectomy]

Bronchopleural fistula is certainly the most important and specific complication following total pneumonectomy. In order to reduce this risk a systematic protection of bronchial suture by means of muscular flap transposition is suggested. The authors report 15 cases of total pneumonectomy for lung cancer at different localization. In all the patients a bronchomuscular plasty was used to protect the bronchial suture. The anterolateral body of latissimus dorsi, when it was possible, was preferred for the following reasons: 1) it makes the suture of the main bronchus greatly resistant; 2) it makes easier the obliteration of the pleural cavity; 3) its transposition is rapid and easy. In only one case a diaphragmatic flap was transposed together with its vascular and nervous system giving rise to a phrenic paralysis. Although few cases are reported, the results are successful and encourage the application of this procedure in future.

Tracheal rupture secondary to orotracheal intubation

A case of tracheal rupture due to orotracheal intubation performed for anaesthesiological procedures is described. It is very likely that this rare complication was favoured by some anatomical factors, which were responsible for a difficult intubation. Tracheal rupture was diagnosed by endoscopy and treated by a decompressive tracheostomy.

[Recurrent biliary calculi]

The Authors report two cases of recurrent bile duct stones and discuss about the diagnosis and treatment of this infrequent disease. Although diagnostic and management procedures are similar to those commonly used in all types of biliary stones, therapeutical options may be different in relation to the different clinical pictures. The Authors strongly suggest that bilioenteric anastomosis and endoscopic sphincterotomy are the best procedures to assure a correct and definitive treatment of recurrent biliary stones. However, the adoption of different diagnostic and therapeutic approaches, rather than univocal schemes, is recommended.

[Meigs' syndrome. A case report]

The authors report on a case of Meigs' syndrome in a patient admitted with vomiting, abdominal pain, peritoneal and right pleural effusion, increased serum levels of CA 125. Surgical excision was successful.

[Does the photoplethysmographic technique show an improvement in the measurement of the indirect blood pressure in intensive care patients?]

In the present report we investigated whether oscillometric and plethysmographic arterial blood pressure measurement techniques yielded different results compared to invasive blood pressure measurements in 18 mechanically ventilated and 14 spontaneously breathing patients. METHODS. Blood pressure was recorded simultaneously with plethysmographic, oscillometric, and invasive systems (FINAPRES 2300, HP 78352A, and 78534A, respectively). Invasive measurements were obtained in the radial artery. Short tubing was chosen in order to avoid transmission errors. The finger cuff of the FINAPRES 2300 was placed on the ipsilateral middle phalanx of the middle finger. The cuff of the oscillometric system was located on the contralateral arm. Differences in arterial blood pressure had been excluded. RESULTS. Histograms of the differences in the various pressure measurements, linear regression, and correlation coefficients were determined for quantitative comparison. The two non-invasive measurement devices (FINAPRES 2300, HP 78352A) yielded similar results in spontaneously breathing patients. In ventilated patients the reliability of oscillometric measurements was worse than that of the photoplethysmographic, especially for diastolic and mean arterial blood pressure values (Table 1, Figs. 2-4). DISCUSSION. The reasons for the differences between invasive and non-invasive measurement techniques are most likely due to problems with cuff handling for the plethysmographic device and the principles of oscillometric measurement. Both methods have to be optimised in hardware and software. However, the photoplethysmographic results showed an improvement in blood pressure measurement in ventilated patients. Due to the remaining deviations between the non-invasive and invasive measurements, especially in critically ill patients in the intensive care unit, direct measurement cannot be replaced by either of the non-invasive methods.

[Rational and mini-invasive approach to the therapy in varicose syndrome: the C.H.I.V.A. treatment]

The principles of the C.H.I.V.A. (Ambulatory conservative and haemodynamic therapy of venous insufficiency) procedure are reported. According to the Authors a careful haemodynamic evaluation of the venous system strictly correlates to the clinical and functional results. In their experience, in fact, results showed no variceal recurrence and a very low rate of complications. Therefore, the C.H.I.V.A. procedure is recommended for most of the patients with lower limb varices.

[Carcinoma of the gastroesophageal junction. General principles of surgical therapy]

On the basis of histo-pathological examinations of postoperative samples following gastrectomy for adenocarcinomas of the esophageal gastric junction, the usefulness of the abdominal approach for this kind of surgical treatment is questioned. Assessment is expressed with other authors about the need for an anatomo-surgical classification of the cardial region, and the need to standardise the different surgical approaches in relation to exeresis location and extent as well as for reconstructive procedures is stressed.

[The use of Mersilene mesh in the treatment of giant laparoceles]

The paper reports on experience with the use of Mersilene mesh in 6 patients with giant laparoceles. Besides being physiologically compatible, Mersilene mesh is recommended when traditional techniques fail. The Rives technique was used, placing the prostheses between the posterior sheath and the rectus muscle; in one case it was inserted under the peritoneum. A good local and general preparation for the operation is recommended. Even though the introduction of prosthetic materials into the body is not always non-injurious, the use of Mersilene mesh is advised because of its easy positioning and the low incidence of complications.

[Fistula following emergency total colectomy: an efficient method of treatment]

A personal case of enterocutaneous fistula secondary to total emergency colectomy is reported with particular emphasis on an effective form of radiological management, based on the percutaneous sclerosing of the fistulous tract using absolute ethanol and a hyperosmotic contrast medium (Angioconray 80%). By this approach a rapid closure of the fistulous tract was obtained. Moreover the procedure was easy to perform, well tolerated by the patient and devoid of untoward side effects.