Flexible switch matrix addressable electrode arrays with organic electrochemical transistor and pn diode technology

Due to their effective ionic-to-electronic signal conversion and mechanical flexibility, organic neural implants hold considerable promise for biocompatible neural interfaces. Current approaches are, however, primarily limited to passive electrodes due to a lack of circuit components to realize complex active circuits at the front-end. Here, we introduce a p-n organic electrochemical diode using complementary p- and n-type conducting polymer films embedded in a 15-μm -diameter vertical stack. Leveraging the efficient motion of encapsulated cations inside this polymer stack and the opposite doping mechanisms of the constituent polymers, we demonstrate high current rectification ratios ([Formula: see text]) and fast switching speeds (230 μs). We integrate p-n organic electrochemical diodes with organic electrochemical transistors in the front-end pixel of a recording array. This configuration facilitates the access of organic electrochemical transistor output currents within a large network operating in the same electrolyte, while minimizing crosstalk from neighboring elements due to minimized reverse-biased leakage. Furthermore, we use these devices to fabricate time-division-multiplexed amplifier arrays. Lastly, we show that, when fabricated in a shank format, this technology enables the multiplexing of amplified local field potentials directly in the active recording pixel (26-μm diameter) in a minimally invasive form factor with shank cross-sectional dimensions of only 50×8 [Formula: see text].

Prognostic role of optic nerve sheath diameter in stroke in emergency department, A case control study

Background

Sonographic measurement of optic nerve sheath diameter (ONSD) can reflect intracranial pressure (ICP) indirectly and determine the neurology intensive care unit (NICU) requirement and mortality in acute ischemic stroke (AIS).

Aim

To demonstrate the effectiveness of ONSD to determine mortality, morbidity, and NICU requirement on patients with the AIS.

Methods

The sonographic ONSD measurements were performed on each patient with AIS, over 18 years old. All patients were categorized according to the Oxfordshire Community Stroke Project (OCSP) classification system. MRI images were examined for increased ICP, and the patients were categorized into two groups as increased ICP (i-ICP) and normal ICP. The ONSD results were evaluated in terms of classifications, outcomes, and prognosis of the patients.

Results

One hundred and five patients were included and 31 (35.2%) were in the i-ICP group. The median ONSDs were 5.26 mm in the i-ICP group and 4.62 mm in the normal ICP group (P < 0.001). The median ONSDs were 5.13 mm in the NICU group and 4.69 mm in the neurology ward (NW) group (P = 0.001). The total anterior circulation infarction (TACI) subgroup had higher ONSDs than the others (TACI: 5.27 mm; PACI: 4.73 mm; POCI: 4.77 mm; and LACI: 4.64 mm, P < 0.001). The NICU requirements were higher in the TACI subgroup. The median ONSD was 5.42 mm in the deceased group (survived: 4.77 mm, P < 0.001).

Conclusion

ONSD may be favorable for predicting the increased ICP and the NICU requirement in OCSP subgroups. Moreover, ONSD can be used to foresee the mortality of AIS.

Which is the most appropriate anterior glenohumeral dislocation reduction technique among three different techniques? A prospective, randomized clinical trial

OBJECTIVES

This study aims to compare three glenohumeral dislocation (GHD) reduction techniques in terms of pain and reduction time and to offer clinicians an idea of the selection of the most appropriate technique.

PATIENTS AND METHODS

This multi-center, prospective, randomized clinical study included a total of 90 patients (55 males, 35 females; median age: 29 years; range, 22 to 41 years) who had isolated anterior GHD without complication between December 2019 and December 2021. The patients were divided into three equal groups (traction-countertraction [TCT], external rotation [ExR], and Cunningham) using the block randomization method, and reductions were performed. Pre-reduction, intra-reduction, and post-reduction Visual Analog Scale (VAS) scores, reduction times, success rates, and complication rates were analyzed.

RESULTS

There was no statistically significant difference among the groups in terms of age (p=0.414), sex (p=0.954), pre-reduction VAS (p=0.175), and post-reduction VAS (p=0.204). The median intra-reduction VAS values in the TCT, the external rotation, and the Cunningham groups were 8 (range, 7 to 9), 5 (range, 4 to 7), and 4 (range, 2.75 to 5), respectively (p<0.001). The median reduction time and IQR were 105 (range, 82.5 to 120) sec for TCT, 270 (range, 232.5 to 300) sec for ExR, and 630 (range, 540 to 780) sec for Cunningham (p=0.001).

CONCLUSION

The fastest, but most painful technique is TCT, while the longest and the least painful technique is Cunningham. An inverse relationship is found between time and pain. Based on these findings, it seems to be reasonable to leave the choice of the ideal reduction technique to the clinician. The clinician should choose the technique to be used according to the conditions in the emergency department.

Flexible ultrasound transceiver array for non-invasive surface-conformable imaging enabled by geometric phase correction

Ultrasound imaging provides the means for non-invasive real-time diagnostics of the internal structure of soft tissue in living organisms. However, the majority of commercially available ultrasonic transducers have rigid interfaces which cannot conform to highly-curved surfaces. These geometric limitations can introduce a signal-quenching air gap for certain topographies, rendering accurate imaging difficult or impractical. Here, we demonstrate a 256-element flexible two-dimensional (2D) ultrasound piezoelectric transducer array with geometric phase correction. We show surface-conformable real-time B-mode imaging, down to an extreme radius of curvature of 1.5 cm, while maintaining desirable performance metrics such as high signal-to-noise ratio (SNR) and minimal elemental cross-talk at all stages of bending. We benchmark the array capabilities by resolving reflectors buried at known locations in a medical-grade tissue phantom, and demonstrate how phase correction can improve image reconstruction on curved surfaces. With the current array design, we achieve an axial resolution of ≈ 2 mm at clinically-relevant depths in tissue, while operating the array at 1.4 MHz with a bandwidth of ≈ 41%. We use our prototype to image the surface of the human humerus at different positions along the arm, demonstrating proof-of-concept applicability for real-time diagnostics using phase-corrected flexible ultrasound probes.

Comparison of the Effects of Aspergillus niger and Aspergillus ficuum on the Removal of Impurities in Feldspar by Bio-beneficiation

Depending on its purity, feldspar has a wide application in industry. Fungi play an important role in the feldspar purification. A bacterial leaching study of feldspar sample from Aydin, Turkey, was conducted to obtain a suitable raw material for industrial applications. XRD analyses indicated that albite (NaAlSi₃O₈) with minor amounts of orthoclase (KAlSi₃O₈), quartz (SiO₂), muscovite (KAl₂(Si₃AlO₁₀)(OH)₂), rutile (TiO₂), and small quantities of weathered clay minerals. This study evaluates bacterial leaching treatment to iron removal from feldspar using Aspergillus niger and Aspergillus ficuum to attain a product suitable for industrial uses. These funguses were tested for organic acid (oxalic and citric acid) production and leaching capabilities of feldspar. The leaching performances of two funguses were compared. Bacterial leaching experiments were performed in 500-mL Erlenmeyer flask at 30 ± 2 °C and 180 rpm agitation under aseptic conditions. In bacterial leaching experiments using A. niger and A. ficuum, 70.13% and 85.09% of the total iron oxides in the feldspar were removed, respectively. As a result, the final iron oxide concentrations in bacterial leaching experiments using A. niger and A. ficuum were 0.095% and 0.047%, respectively (at 5% w/v pulp density, temperature 30 ± 2 °C, A. niger 3 × 10⁷ spores, A. ficuum 5 × 10⁷ spores, and particle size < 63 μm). The use of fungi to remove iron from feldspar has the potential to be an effective method for upgrading the content and the commercial value of the feldspar. The experimental results of this study have provided significant opportunity to use biotechnological approach for producing the feldspar as a feed material for the high-quality ceramic industry.

Emergency medicine physicians' perspectives on subspecialty training: A national survey

BACKGROUND

Subspecialty training (sST) is an accepted educational model for the branches that have completed the maturation period. At the end of a rapid growth and reaching its limits, we wanted to determine the emergency medicine (EM) physicians' thoughts about subspecialty training in EM in Turkey.

METHOD

This is a national cross-sectional survey study conducted in November 2017. Participants were physicians who were receiving or who had completed emergency medicine education.

RESULTS

The response rate was 32% (n = 607) in the study. The rate of attending physicians was 45.1%, resident physicians were 40.2%, and academic staff were 14.7%. Among all the EM physicians, 85.2% noted the need for sST, 9.6% were uncertain about the need, and 5.3% found the need unnecessary. The most frequently requested trainings were toxicology (72.5%), traumatology (71.3%), and critical care (67.4%). After sST, 48.9% of EM physicians requested to work both in the emergency department and in the other relevant department, 36.1% requested to work full-time in the emergency department, and 14.9% requested to work full-time in the other relevant department.

CONCLUSION

The great majority of EM physicians believed in the need for sST in Turkey. There were two primary reasons for wanting to apply for sST: first, and most frequently, was the contribution to advanced training, and second, was avoiding problems in the daily practice of EM.

Perioperative outcomes of major hepatic resections under low central venous pressure anesthesia: blood loss, blood transfusion, and the risk of postoperative renal dysfunction

BACKGROUND

We have previously demonstrated that maintenance of a low central venous pressure (LCVP) combined with extrahepatic control of venous outflow reduced the overall blood loss during major hepatic resections. This study examined the overall outcomes and, in particular, renal morbidity associated with a large series of consecutive major liver resections performed with this approach. In addition, the rationale for the anesthetic management to maintain LCVP was carefully reviewed.

STUDY DESIGN

All major hepatectomies performed between December 1991 and April 1997 were reviewed. The prospective Hepatobiliary Surgical Service database was merged with the Memorial Hospital Laboratory and Blood Bank databases to yield the nature of the operation, blood loss, blood product transfusions, outcomes, and levels of preoperative, postoperative, and discharge serum creatinine and blood urea nitrogen.

RESULTS

A total of 496 LCVP-assisted major liver resections were performed, with no intraoperative deaths and an in-hospital mortality rate of 3.8%. The median blood loss was 645 mL. Sixty-seven percent of the patients did not require perioperative blood transfusion during surgery and the immediate 12 hours after surgery. The median number of blood transfusions was 2. Only 3% of the patients experienced a persistent and clinically significant increase in serum creatinine possibly attributable to the anesthetic technique. Renal failure directly attributable to the anesthetic technique did not occur.

CONCLUSIONS

Major resection with LCVP allowed easy control of the hepatic veins before and during parenchymal transection. The anesthetic technique, designed to maintain LCVP during the critical stages of hepatic resection, not only helped to minimize blood loss and mortality but also preserved renal function.