Shrink polymer based electrochemical sensor for point-of-care detection of prostate-specific antigen.

There is a growing but unmet need for point-of-care detection of prostate-specific antigen (PSA) in body fluid which may facilitate early diagnosis and therapy of prostate cancer in a cost-effective and user-friendly way. Low sensitivity and narrow detection range limits applications of point-of-care testing in practice. Here, an immunosensor is first presented based on shrink polymer and integrated into a miniaturized electrochemical platform for detecting PSA in clinical samples. The sensing electrode was prepared by sputtering a gold film on shrink polymer, followed by heating to shrink the electrode to a small size with wrinkles from nano-scale to micro-scale. These wrinkles can be directly regulated by the thickness of the gold film with high specific areas for enhancement of antigen-antibody binding (3.9 times). A distinct difference between electrochemical active surface area (EASA) and response to PSA of shrink electrodes was observed and discussed. The electrode was treated with air plasma and modified with self-assembled graphene to further enhance the sensor's sensitivity (10.4 times). The shrink sensor with gold 200 nm thick integrated into the portable system was validated by a label-free immunoassay for detection of PSA in 20 µL serum within 35 mins. It exhibited a limit of detection of 0.38 fg/mL, the lowest among label-free PSA sensors, and a wide linear response from 10 fg/mL to 1000 ng/mL. Moreover, the sensor demonstrated reliable assay results in clinical serums, comparable to the commercial chemiluminescence instrument, confirming its feasibility for clinical diagnosis.

The Efficacy and Safety of Sacubitril/Valsartan in Heart Failure Patients: A Review.

Heart failure (HF) is one of the leading causes of morbidity and mortality worldwide. Sacubitril/valsartan, an angiotensin receptor-neprilysin inhibitor, has been approved for the treatment of HF. At present, there have been few systematic and detailed reviews discussing the efficacy and safety of sacubitril/valsartan in HF. In this review, we first introduced the pharmacological mechanisms of sacubitril/valsartan, including the reduction in the degradation of natriuretic peptides in the natriuretic peptide system and inhibition of the renin-angiotensin system. Then, we summarized the efficacy of sacubitril/valsartan in HF patients with reduced ejection fraction (HFrEF) or preserved ejection fraction (HFpEF) including the reduction in risks of mortality and hospitalization, reversal of cardiac remodeling, regulation of biomarkers of HF, improvement of the quality of life, antiarrhythmia, improving renal dysfunction and regulation of metabolism. Finally, we discussed the safety and tolerability of sacubitril/valsartan in the treatment of HFrEF or HFpEF. Compared with ACEIs/ARBs or placebo, sacubitril/valsartan showed good safety and tolerability, although the risk of hypotension might be high. In conclusion, the overwhelming majority of studies show that sacubitril/valsartan is effective and safe in the treatment of HFrEF patients but that it has little benefit in HFpEF patients. Sacubitril/valsartan will probably be a promising anti-HF drug in the near future.

Progress of shrink polymer micro- and nanomanufacturing.

Traditional lithography plays a significant role in the fabrication of micro- and nanostructures. Nevertheless, the fabrication process still suffers from the limitations of manufacturing devices with a high aspect ratio or three-dimensional structure. Recent findings have revealed that shrink polymers attain a certain potential in micro- and nanostructure manufacturing. This technique, denoted as heat-induced shrink lithography, exhibits inherent merits, including an improved fabrication resolution by shrinking, controllable shrinkage behavior, and surface wrinkles, and an efficient fabrication process. These merits unfold new avenues, compensating for the shortcomings of traditional technologies. Manufacturing using shrink polymers is investigated in regard to its mechanism and applications. This review classifies typical applications of shrink polymers in micro- and nanostructures into the size-contraction feature and surface wrinkles. Additionally, corresponding shrinkage mechanisms and models for shrinkage, and wrinkle parameter control are examined. Regarding the size-contraction feature, this paper summarizes the progress on high-aspect-ratio devices, microchannels, self-folding structures, optical antenna arrays, and nanowires. Regarding surface wrinkles, this paper evaluates the development of wearable sensors, electrochemical sensors, energy-conversion technology, cell-alignment structures, and antibacterial surfaces. Finally, the limitations and prospects of shrink lithography are analyzed.

Flexible micro-sensors with self-assembled graphene on a polyolefin substrate for dopamine detection.

The electrochemical sensing of dopamine is of great significance for studying and treating neurochemical diseases due to its potential feasibility for in vivo diagnostics. The commonly used sensors suffer from low sensitivity, the interference of ascorbic acid, and poor flexibility. In this paper, the function of electrode substrates including polyolefin, polystyrene, and polyethylene terephthalate films were investigated for their ability to improve electrochemical performances and provide favorable flexibility. The interference from ascorbic acid was cut down to a minimum by reducing the electrochemical resistance and the ascorbic acid diffusion current. The results demonstrate that gold electrodes prepared on polyolefin films exhibit a low charge transfer resistance of about 20 Ω, high sensitivity of dopamine detection (7.8 µA/µM), which is about 312 folds that of silicon electrode (0.025 µA/µM) and excellent flexibility. Having regulated the fabrication process of graphene by altering self-assembly layers and modification area, the sensor shows a dopamine detection limit of 0.11 µM in the presence of 500 µM ascorbic acid, and a sensitivity of 0.33 µA/µM. This work is valuable for the further improvement of the sensitivity and selectivity of the electrochemical sensor.

Optimal central venous pressure during partial hepatectomy for hepatocellular carcinoma.

BACKGROUND: Low central venous pressure (CVP) affects hemodynamic stability and tissue perfusion. This prospective study aimed to evaluate the optimal CVP during partial hepatectomy for hepatocellular carcinoma (HCC). METHODS: Ninety-seven patients who underwent partial hepatectomy for HCC had their CVP controlled at a level of 0 to 5 mmHg during hepatic parenchymal transection. The systolic blood pressure (SBP) was maintained, if possible, at 90 mmHg or higher. Hepatitis B surface antigen was positive in 90 patients (92.8%) and cirrhosis in 84 patients (86.6%). Pringle maneuver was used routinely in these patients with clamp/unclamp cycles of 15/5 minutes. The average clamp time was 21.4+/-8.0 minutes. These patients were divided into 5 groups based on the CVP: group A: 0-1 mmHg; B: 1.1-2 mmHg; C: 2.1-3 mmHg; D: 3.1-4 mmHg and E: 4.1-5 mmHg. The blood loss per transection area during hepatic parenchymal transection and the arterial blood gas before and after liver transection were analyzed. RESULTS: With active fluid load, a constant SBP ≥90 mmHg which was considered as optimal was maintained in 18.6% in group A (95% CI: 10.8%-26.3%); 39.2% in group B (95% CI: 29.5%-48.9%); 72.2% in group C (95% CI: 63.2%-81.1%); 89.7% in group D (95% CI: 83.6%-95.7%); and 100% in group E (95% CI: 100%-100%). The blood loss per transection area during hepatic parenchymal transection decreased with a decrease in CVP. Compared to groups D and E, blood loss in groups A, B and C was significantly less (analysis of variance test, P<0.05). Compared with the baseline, the blood oxygenation decreased significantly when the CVP was reduced. Base excess and HCO3- in groups A and B were significantly decreased compared with those in groups C, D and E (P<0.05). CONCLUSION: In consideration of blood loss, SBP, base excess and HCO3-, a CVP of 2.1-3 mmHg was optimal in patients undergoing partial hepatectomy for HCC.