Proton Conducting Neuromorphic Materials and Devices.

Neuromorphic computing and artificial intelligence hardware generally aims to emulate features found in biological neural circuit components and to enable the development of energy-efficient machines. In the biological brain, ionic currents and temporal concentration gradients control information flow and storage. It is therefore of interest to examine materials and devices for neuromorphic computing wherein ionic and electronic currents can propagate. Protons being mobile under an external electric field offers a compelling avenue for facilitating biological functionalities in artificial synapses and neurons. In this review, we first highlight the interesting biological analog of protons as neurotransmitters in various animals. We then discuss the experimental approaches and mechanisms of proton doping in various classes of inorganic and organic proton-conducting materials for the advancement of neuromorphic architectures. Since hydrogen is among the lightest of elements, characterization in a solid matrix requires advanced techniques. We review powerful synchrotron-based spectroscopic techniques for characterizing hydrogen doping in various materials as well as complementary scattering techniques to detect hydrogen. First-principles calculations are then discussed as they help provide an understanding of proton migration and electronic structure modification. Outstanding scientific challenges to further our understanding of proton doping and its use in emerging neuromorphic electronics are pointed out.

Role of Interventional Radiology (IR) in vascular emergencies among cirrhotic patients.

Gastrointestinal hemorrhage remains one of the most common causes of morbidity and mortality among patients with liver cirrhosis. Mostly, these patients bleed from the gastroesophageal varices. However, nonvariceal bleeding is also more likely to occur in these patients. Because of frequent co-existing coagulopathy, cirrhotics are more prone to bleed from a minor vascular injury while performing percutaneous interventions. Ultrasound-guided bedside vascular access is an essential procedure in liver critical care units. Transjugular portosystemic shunts (TIPS) with/without variceal embolization is a life-saving measure in patients with refractory variceal bleeding. Whenever feasible, balloon-assisted retrograde transvenous obliteration (BRTO) is an alternative to TIPS in managing gastric variceal bleeding, but without a risk of hepatic encephalopathy. In cases of failed or unfeasible endotherapy, transarterial embolization using various embolic agents remains the cornerstone therapy in patients with nonvariceal bleeding such as ruptured hepatocellular carcinoma, gastroduodenal ulcer bleeding, and procedure-related hemorrhagic complications. Among various embolic agents, N-butyl cyanoacrylate (NBCA) enables better vascular occlusion in cirrhotics, even in coagulopathy, making it a more suitable embolic agent in an expert hand. This article briefly entails the different interventional radiological procedures in vascular emergencies among patients with liver cirrhosis.

Emergency endovascular and percutaneous urological interventions: A pictorial review.

Emergency endovascular and percutaneous urological interventions encompass various diagnostic and therapeutic procedures to address various genitourinary conditions. These urological interventions are life-saving in addressing complications following biopsy, post-nephrectomy, post-transplant, and post-trauma. Compared to other surgical fields, there are relatively fewer urological emergencies. However, they require prompt radiological diagnosis and urgent interventions. This pictorial essay emphasizes various urological emergencies and urgent interventional management.

Is salvage Plug-Assisted Retrograde Transvenous Obliteration (PARTO) safe and effective for bleeding gastric varices ?- A preliminary single-center experience.

BACKGROUND: Vascular plug-assisted retrograde transvenous obliteration (PARTO) obliterates the gastric varices and portosystemic shunt, thus resulting in a lower rebleeding rate than endoscopic glue/sclerotherapy. AIMS: To evaluate the safety and efficacy of PARTO as salvage therapy in liver cirrhosis with gastric variceal bleed (GVB) after failed endotherapy. We assessed the clinical success rate and changes in liver function at 6- months. MATERIALS AND METHODS: Patients who underwent salvage PARTO after failed endotherapy for GVB (between December 2021 and November 2022) were searched and analyzed from the hospital database. Clinical success rate and rebleed rate were obtained at six months. Child-Pugh score (CTP) and Model for end-stage liver disease (MELD) score were calculated and compared between baseline and 6-month follow-up. RESULTS: Fourteen patients (n = 14, Child-Pugh class A/B) underwent salvage PARTO. Nine had GOV-2, and five had IGV-1 varices. The mean shunt diameter was 11.6 ± 1.6 mm. The clinical success rate of PARTO was 100% (no recurrent gastric variceal hemorrhage within six months). No significant deterioration in CTP (6.79 ± 0.98 vs. 6.21 ± 1.52; p = 0.12) and MELD scores (11.5 ± 4.05 vs. 10.21 ± 3.19; p = 0.36) was noted at 6 months. All patients were alive at 6 months. One patient (n = 1, 7.1%) bled from esophageal varices after three days of PARTO and was managed with variceal banding. 21.4% (3/14) patients had progression of esophageal varices at 6 months requiring prophylactic band ligation. Three patients (21.4%) had new onset or worsening ascites and responded to low-dose diuretics therapy. CONCLUSIONS: PARTO is a safe and effective procedure for bleeding gastric varices without any deterioration in liver function even after six months. Patient selection is critical to prevent complications. Further prospective studies with larger sample size are required to validate our findings.

Uterine Artery Pseudoaneurysm after Total Abdominal Hysterectomy Managed by Ultrasound-guided Percutaneous Glue Injection.

Uterine artery pseudoaneurysm (UAP) following abdominal hysterectomy is an uncommon complication. However, it can cause life-threatening bleeding, necessitating early diagnosis and intervention. Imaging is vital in its prompt diagnosis and aids in planning interventions. Here, we describe a case of recurrent massive per-vaginal bleeding from a left UAP developed following total abdominal hysterectomy and bilateral salpingo-oophorectomy. Bleeding was successfully managed with percutaneous ultrasound-guided glue (N-butyl cyanoacrylate) injection into the aneurysmal sac. The patient is doing well without any recurrent bleeding.

Lower extremity pseudoaneurysms and their interventional radiological management: a pictorial review.

Lower extremity pseudoaneurysms (PsAs) are mostly developed after traumatic or iatrogenic injury to the arteries. Unless treated, they can be complicated by adjacent mass effects, distal embolism, secondary infection, and rupture. Imaging helps in the diagnosis and planning of therapeutic intervention. Ultrasonography (USG) is often diagnostic, while CT angiography aids in vascular mapping required for intervention. Image-guided therapy offers to manage these pseudoaneurysms in a minimally invasive approach, obviating the need for surgery. A smaller, superficial, and narrow-necked PsA can easily be managed with local USG-guided compression or thrombin injection. When the percutaneous approach is not a feasible option, PsA from expendable arteries can also be managed with coiling or glue injection. Wide-necked PsA from an unexpendable artery necessitates stent graft placement, although coiling of the neck may be a viable and cheaper alternative for a long- and narrow-necked PsA. Presently, vascular closure devices are also used to seal a small arterial rent through a direct percutaneous approach. This pictorial review entails various techniques to deal with lower extremity pseudoaneurysms. An idea about the various intervention radiological approaches will help in choosing appropriate methods to tackle lower extremity pseudoaneurysms.

Bedside USG-Guided Paracentesis - A Technical Note for Beginners.

Paracentesis is a routinely performed low-risk daycare procedure most commonly performed in patients with cirrhosis. Although uncommon, devastating bleeding complications may occur, particularly in patients with coagulopathy. Hence to avoid any such complication, it is important for the intervention radiologists, as well as clinicians, particularly beginners, to have basic knowledge of the major anterior abdominal wall arteries, their course, and their sonographic appearance. Here, we briefly describe the relevant abdominal wall anatomy and sonographic planes to use for paracentesis.

The role of "penumbra sign" and diffusion-weighted imaging in adnexal masses: do they provide a clue in differentiating tubo-ovarian abscess from ovarian malignancy?

PURPOSE: To evaluate the role of "penumbra sign", diffusion-weighted imaging (DWI), and the apparent diffusion coefficient (ADC) value in differentiating tubo-ovarian abscess (TOA) from ovarian malignancy. MATERIAL AND METHODS: Thirty-six patients with 50 adnexal masses (tubo-ovarian abscess, n = 24; ovarian malignancy, n = 26), who underwent magnetic resonance imaging (MRI) with DWI, were retrospectively evaluated. "Penumbra sign" (hyperintense rim on T1W images), diffusion restriction, and mean apparent diffusion coefficient (ADC) values from cystic (c-ADC) and solid (s-ADC) components were evaluated for all the masses. RESULTS: "Penumbra sign" on T1W images was significantly more common in the TOA group (n = 21, 87.5%) than in the ovarian malignancy group (n = 2, 7.7%) (p < 0.001). Similarly, diffusion restriction in the cystic component was more frequent in the TOA group (n = 24, 100% vs. n = 2, 10.5%; p < 0.001). In contrast, diffusion restriction in the solid component was more common in the ovarian malignancy group (n = 5, 20.8% vs. n = 26, 100%; p < 0.001). The mean c-ADC value was significantly lower in TOAs (p < 0.001). A c-ADC value of 1.31 × 10-3 mm2/s may be an optimal cut-off in distinguishing TOAs from ovarian malignancies. Conversely, the mean s-ADC value was significantly lower in the ovarian malignancy group (p < 0.001). An s-ADC value of 0.869 × 10-3 mm2/s may be an optimal cut-off in differentiating ovarian malignancies from TOAs (p < 0.001). ROC curve analysis showed that c-ADC values had a higher diagnostic accuracy than s-ADC values. CONCLUSIONS: "Penumbra sign" on T1W images, diffusion characteristics, and ADC values provide important clues in addition to conventional MR imaging features in differentiating TOA from ovarian malignancy.

Tuberculous aortitis with jejunal artery mycotic pseudoaneurysm managed by endovascular coil embolisation.

Mycotic aneurysm in a visceral artery due to tuberculosis (TB) is a rare occurrence. Imaging plays a critical role in its diagnosis. Over the last few years, minimally invasive interventional radiological treatment has replaced more invasive surgical procedures. Here, we report a case presenting with abdominal pain, diagnosed with jejunal artery mycotic pseudoaneurysm (PSA) secondary to TB, managed by endovascular coiling. Coil embolisation of the superior mesenteric artery branch was done using three coils, closing both the front door, back door and sac of the mycotic aneurysm. Visceral PSA following TB infection is rare and can be fatal if left untreated. Coil embolisation is a minimally invasive procedure with a high success rate and comparatively fewer complications.

Iatrogenic pseudoaneurysm after bone biopsy managed with endovascular coil embolisation.

Bone marrow biopsy (BMB) is a routinely performed procedure, with the preferred site being the posterior superior iliac crest. Uncommonly, it may be complicated by haemorrhagic complications, especially in patients with coagulopathy. Here, we present a case of pelvic haematoma following a BMB due to the injury of the right internal iliac artery. Endovascular embolisation was performed on an urgent basis to manage this complication. The bleeding stopped following the embolisation.

A lung cyst harbouring a congenital pulmonary varix.

A non-smoker man in his second decade presented to a medical centre with intermittent haemoptysis over 2 years. The haemoptysis was infrequent initially to be ignored, but later, the episodes increased in amount and frequency. Routine blood tests including coagulation profile showed normal results. The chest radiography and echocardiography were normal. The contrast-enhanced CT scan of the chest showed a cystic lesion with intracystic abnormality and surrounding ground-glass opacity in the left upper lobe. The CT pulmonary angiography and invasive pulmonary angiography showed the abnormality to be a dilated pulmonary vessel draining into the left atrium, thereby confirming the diagnosis of congenital pulmonary varix contained within a lung cyst. The patient underwent a successful lobectomy following which he experienced no further haemoptysis.