Molecular Visual Sensing, Boolean Logic Computing, and Data Security Using a Droplet-Based Superwetting Paradigm

Inspired by information processing and logic operations of life, many artificial biochemical systems have been designed for applications in molecular information processing. However, encoding the binary synergism between matter, energy, and information in a superwetting system remains challenging. Herein, a superwetting paradigm was proposed for multifunctional applications including molecular visual sensing and data security on a superhydrophobic surface. A Triton X-100-encapsulated gelatin (TeG) hydrogel was prepared and selectively decomposed by trypsin, releasing the surfactant to decrease the surface tension of a droplet. Integrating the droplet with the superhydrophobic surface, the superwetting behavior was utilized for visual detection and information encoding. Interestingly, the proposed TeG hydrogel can function as an artificial gelneuron for molecular-level logic computing, where the combination of matters (superhydrophobic surface, trypsin, and leupeptin) acts as inputs to interact with energy (liquid surface tension and solid surface energy) and information (binary character), resulting in superwettability transitions (droplet surface tension, contact angle, rolling angle, and bounce) as outputs. Impressively, the TeG gelneuron can be further developed as molecular-level double cryptographic steganography to encode, encrypt, and hide specific information (including the maze escape route and content of the classical literature) due to its programmability, stimuli responsive ability, and droplet concealment. This study will encourage the development of advanced molecular paradigms and their applications, such as superwetting visual sensing, molecular computing, interaction, and data security.

[Detection of drug resistance genes of mycobacterium tuberculosis by rolling circle amplification technique with multicolor fluorescent probes]

The aim of this study was to construct a simple, rapid and ultra-sensitive optical biosensing technique based on rolling circle amplification (RCA), and to apply it to multiple detection of drug-resistant genes of mycobacterium tuberculosis. The common mutation sites of isoniazid, rifampicin and streptomycin resistance genes are katG315 (AGC➝ACC), rpoB531 (CAC➝TAC) and rpsL43 (AAG➝AGG). For these three gene sites, from February 2020 to May 2021, in the Department of Laboratory Medicine of the First Affiliated Hospital of Army Military Medical University, the padlock probe (PLP), primers and capture probes were designed. And a solid-phase RCA constant temperature amplification reaction system based on magnetic beads was constructed and the experimental parameters were optimized. The RCA products were accurately captured by the multicolor fluorescent probes (Cy3/Cy5/ROX), and the single-tube multiple detection of three mutation genes was realized. The sensitivity, specificity and linear range of this method were further verified. The results showed that the response range of katG315 in the same reaction system ranged from 1.0 pmol/L to 0.1 nmol/L. The response range of rpoB531 and rpsL43 ranged from 1.0 pmol/L to 50.0 pmol/L and 1.0 pmol/L to 20.0 pmol/L, and the method had good specificity and sensitivity, and could accurately identify single base mutations in mixed targets, with the minimum detection limit as low as 1.0 pmol/L. The recoveries of simulated serum samples were 95.0%-105.2%. In conclusion, the constant temperature amplification multiple detection method constructed in this study can quickly realize the single-tube multiple detection of three drug resistance mutation sites. This technology is low-cost, simple and rapid, and does not rely on large equipment, providing a new analysis method for pathogen drug resistance gene detection.

[Construction of microRNA-21 terahertz metamaterial sensing method based on duplex-specific nuclease triggered rolling circle amplification]

Objective: To construct of a terahertz metamaterial sensing method for detection of microRNA-21 (miRNA-21) based on duplex-specific nuclease triggered rolling circle amplification. Methods: First, a THz metamaterial sensing method was constructed, and verified by polyacrylamide gel electrophoresis and zeta potential; after optimizing the detection conditions of the sensor, different concentrations of miRNA-21 and other different miRNAs were detected. And this biosensor was compared with other miRNA detection methods; finally, the recovery rate of the biosensor was evaluated. Results: Under the optimal experimental conditions, through the dual signal amplification strategy of duplex-specific nuclease (DSN) cycle recognition and rolling circle amplification (RCA), the THz metamaterial sensor has a response range of 10 fmol/L to 10 nmol/L to the target miRNA-21, with a detection limit of 8.49 fmol/L. And the biosensor has good specificity with the ability to recognize the target miRNA-21 from a variety of microRNAs. And the experiment with recovery rate from 94.33% to 115.33% has been further verified in commercial human serum samples. Conclusion: The terahertz biosensor can achieve highly sensitive and specific detection of the target miRNA-21, which proves the potential for label-free diagnosis and early warning of miRNA-related diseases.

Different CO2 acclimation strategies in juvenile and mature leaves of Ottelia alismoides

The freshwater macrophyte, Ottelia alismoides, is a bicarbonate user performing C4 photosynthesis in the light, and crassulacean acid metabolism (CAM) when acclimated to low CO₂. The regulation of the three mechanisms by CO₂ concentration was studied in juvenile and mature leaves. For mature leaves, the ratios of phosphoenolpyruvate carboxylase (PEPC) to ribulose-bisphosphate carboxylase/oxygenase (Rubisco) are in the range of that of C4 plants regardless of CO₂ concentration (1.5-2.5 at low CO₂, 1.8-3.4 at high CO₂). In contrast, results for juvenile leaves suggest that C4 is facultative and only present under low CO₂. pH-drift experiments showed that both juvenile and mature leaves can use bicarbonate irrespective of CO₂ concentration, but mature leaves have a significantly greater carbon-extracting ability than juvenile leaves at low CO₂. At high CO₂, neither juvenile nor mature leaves perform CAM as indicated by lack of diurnal acid fluctuation. However, CAM was present at low CO₂, though the fluctuation of titratable acidity in juvenile leaves (15-17 µequiv g^-1 FW) was slightly but significantly lower than in mature leaves (19-25 µequiv g^-1 FW), implying that the capacity to perform CAM increases as leaves mature. The increased CAM activity is associated with elevated PEPC activity and large diel changes in starch content. These results show that in O. alismoides, carbon-dioxide concentrating mechanisms are more effective in mature compared to juvenile leaves, and C4 is facultative in juvenile leaves but constitutive in mature leaves.

[Relationship between gut origin bacteria and wound infection after thermal injury]

The pUC19 plasmid vector trace with restriction map analysis and fluorescence labelling bacteria method were applied to study the relationship between the gut origin bacteria and wound infection. According to the characteristic of pUC19 plasmid, a special animal model was designed. 110 Wistar rats received 30% TBSA full thickness burns. On hours 6, 12, 24, 48 and day 12 postburn, injured animal were killed. Subeschar tissue homogenates were examined under fluorescence microscope, and bacterial culture, isolation of plasmids and restriction map analysis were also carried out. The results show that during early stage of burns, 32.5% of fluorescence labelling bacteria and 10.81% of pUC19 plasmid vectors could be detected from the subeschar specimens. 12 day postburn, the detectable rage of pUC19 plasmid vector increased to 62.5%. Beside the factor of early colonization, the contaminative route form gut perineum and then wounds should be considered.

Monitoring and control of infection in patients after renal transplantation

Infection is a leading cause of death of renal transplantation and how to control it is still an urgent problem to be solved. Bacteria culture, computerized modified McGuckin's monitoring methods, OKT monoclonal antibody technique and radioimmunoassay (RIA) were used on studying the cause, monitoring and prevention of the infection. Results showed that 22 out of 24 cases (91.7%) were colonized by Gram-negative bacilli in pharynx and groin region. Of them, 15 were infected with the same bacteria in wound, urine, blood and lung. Six out of 7 cases with serious infection were colonized by Gram-negative bacilli on the surface of the whole body. The computerized modified McGuckin's method predicted and analyzed the infection outbreak much more fast and accurate, with a rate of over 80%. Helper/suppressor lymphocyte ratio of 1.08 was taken as a threshold value for the diagnosis of infection. The results suggested that the change of skin flora is closely related with the infection. Monitoring the alteration of skin flora is an effective method for the prevention and control of severe infection. The pharynx and groin regions of the patients are stable reservoirs of Gram-negative bacilli which may cause infection easily. Computerized quantitative analysis may increase the efficiency and accuracy of infection surveillance. In order to preserve the immune system as much as possible and prevent rejection of transplant graft, proper use of immunosuppressive drugs and regulation of the immune system of the patients are the key for preventing infection.

[Cytological features of small cell lung cancer--relation between nuclear chromatin change and chemotherapeutic effect]

This paper describes the relation between the cytologic features, change of chromatin and effect of chemotherapy in 75 cases of small cell lung cancer. Basing on the microscopic changes of the chromatin in the cancer cells, 4 types were observed: (1) chromatin evenly distributed with fine granules (2) chromatin evenly distributed with rough granules (3) chromatin sparsely distributed with rough granules (4) ink spot-like nuclei. Type 1 was found in 75.7% of the responders to chemotherapy while Type 3 was frequently observed in 69.2% of the non-responders. The results suggest that the changes of nuclear chromatin be used as an index to predict the response to chemotherapy, conforming to Takeshi's observation. Yet, in this series, the exfoliative cells were obtained from the sputum rather than Takeshi's brush during bronchoscopy. The authors believe that the changes of chromatin may be observed clearly if the sputum is fresh, smeared promptly and stained in the standard way.

Age-dependence of the chronotropic response to noradrenaline, acetylcholine and transmural stimulation in isolated rabbit atria

The chonotropic response to noradrenaline, tyramine, acetylcholine and transmural electrical stimulation was compared in atria isolated from rabbits at different stages of developmental after birth (day 2 to day 210). Pacemaker rates understeady state conditions were related inversely to days after birth; the rate in atria from rabbits at day 2 was significantly greater than that at days 10-210. The rate of neonatal rabbit atria was not significantly reduced by propranolol and the positive chontropic response to noradrenaline was not significantly reduced by propranolol and the positive chronotropic response to noradrenaline was not significantly different in atria from ages of rabbits as far as threshold concentrations for inducing tachycardia and ED50's were concerned. The maximum rate induced by noradrenaline was higher in neonatal rabbit atria than in adult rabbit atria. The effect of tyramine was approx. the same regardless of age. Increase in the pacemaker rate induced by transmural neural stimulation varied directly with age. The negative chronotropic effect of acetylcholine was greater in neonatal than in adult rabbit atria; the ED50 in the former was significantly less than in the latter. Bradycardia induced by transmural stimulation of intracardiac cholinergic nerves was related directly to age. Tachycardia in the neonatal rabbit atria may be due to electrogenic characteristics of pacemaker cells which differ from those in adult rabbit atria. Our evidence strongly suggests that the adrenergic and cholinergic nerves innervating the S-A node develop at an early postnatal stage in the rabbit.

Serotonin antagonism in isolated canine cerebral arteries

In helically-cut strips of canine cerebral arteries, the dose-response curve of serotonin was not influenced by 10(-7) M phentolamine but was slightly moved to the right and downward at 10(-6) M. The contractile response to serotonin was unaffected by cocaine (3 X 10(-6)M), atropine (10(-6) M) and propranolol (10(-6) M). The addition of lysergic acid diethylamide (LSD), ergotamine and methysergide caused a dose-dependent contraction. Treatment with LSD (10(-9) and 10(-8) M), ergotamine (10(-10) to 10(-8) M) and methysergide (10(-8) to 10(-6) M) shifted the dose-response curve of serotonin to the right and downward in a dose-dependent manner. The inhibitory effect of methysergide was reversed by washing, while that of ergotamine was not reversed. Apparent pA2 values of LSD, ergotamine and methysergide were 9.17, 9.63 and 7.92, respectively. Contractile responses to 20 mM K+ were not significantly influenced by these blocking agents even in the highest concentrations used. It may be concluded that an alpha-adrenergic mechanism is not involved in the genesis of serotonin-induced contractions and that serotonin acts directly on serotonergic receptors in canine cerebral arteries.