Research progress on insect visual electrophysiological techniques.

Insect visual electrophysiological techniques are important to study the electrical characteristics of photoreceptor cells and visual neurons in insects, including electroretinography (ERG) and microelectrode intracellular recording (MIR). ERG records the changes of voltage or electric current in the retina of insects in response to different light stimuli, which occurs outside the cell. MIR records the changes in individual photoreceptor cells or visual neurons of an insect exposed to different lights, which occurs inside the cell. Insect visual electrophysiological techniques can explore the mechanism of electrophysiological response of insects' vision to light and reveal their sensitive light spectra and photoreceptor types. This review introduced the basic structure and the principle of ERG and MIR, and summarized their applications in insect researches in the past 20 years, which would provide references for elucidating the mechanism of light perception in insects and the use of insect phototropism to control pests.

Caterpillar Responses to Gustatory Stimuli in Potato Tuber Moths: Electrophysiological and Behavioral Insights.

This research investigates how fourth-instar larvae of the potato tuber moth, Phthorimaea operculella, respond to plant secondary metabolites (sucrose, glucose, nicotine, and tannic acid) both in terms of gustatory electrophysiology and feeding behavior. The objective is to establish a theoretical foundation for employing plant-derived compounds in potato tuber moth control. We employed single-sensillum recording techniques and dual-choice leaf disk assays to assess the gustatory electrophysiological responses and feeding preferences of these larvae towards the mentioned compounds. Sensory neurons responsive to sucrose, glucose, nicotine, and tannic acid were identified in the larvae's medial and lateral sensilla styloconica. Neuronal activity was influenced by stimulus type and concentration. Notably, the two types of sensilla styloconica displayed distinct response patterns for sucrose and glucose while they had similar firing patterns towards nicotine and tannic acid. Sucrose and glucose significantly promoted larval feeding, while nicotine and tannic acid had significant inhibitory effects. These findings demonstrate that the medial and lateral sensilla styloconica house sensory neurons sensitive to both feeding stimulants and inhibitors, albeit with differing response profiles and sensitivities. This study suggests that sucrose and glucose are promising candidates for feeding stimulants, while nicotine and tannic acid show potential as effective feeding inhibitors of P. operculella larvae.

[Research progress on insect single sensillum recording.] / æ˜†è™«å•ä¸ªæ„Ÿè§‰å™¨è®°å½•æŠ€æœ¯ç ”ç©¶è¿›å±•.

Single sensillum recording is an insect extracellular electrophysiological technique, which can measure the electrophysiological responses of a single sensillum to stimuli in insects. It can help explore the electrophysiologi-cal response mechanism of insect olfactory and taste receptors to different semiochemicals. Combined with other techniques, it can be used to understand the molecular genetic mechanisms of olfactory responses, as well as to develop behavior regulators and volatile organic compound biosensors. In this review, we proposed the basic structure and the principle of single sensillum recording, and summarized its applications in insect studies, aiming to provide the foundation for understanding the mechanisms and applications in insect perception of semiochemicals.

An ultra-sensitive selective fluorescent sensor based on a 3D zinc-tetracarboxylic framework for the detection and enrichment of trace Cu2+ in aqueous media.

Herein, a novel and fluorescent zinc-organic framework sensor [Zn3(µ3-Hbptc)2(µ2-4,4'-bpy)2(H2O)4]n·2nH2O (1) (H4bptc = 2,3,3',4'-biphenyl tetracarboxylic acid, 4,4'-bpy = 4,4'-bipyridine) is synthesized and characterized, demonstrating its excellent fluorescence performance for Cu2+ detection and the enrichment of Cu2+ in aqueous media. The fluorescence intensity of 1 can be selectively quenched by Cu2+ in a linear range of Cu2+ concentrations of 0-0.7 µM. The limit of detection (LOD) value is as low as 32.4 nM, which is superior to those of most of the fluorescent sensors based on metal-organic frameworks (MOFs). It is also far below the maximum allowable concentration of Cu2+ in drinking water as defined by the U.S. Environmental Protection Agency (EPA) and the World Health Organization (WHO), so it is employed for the detection of Cu2+ in actual water samples. More importantly, the nature of the interaction between the active coordination site (COO-) of 1 and Cu2+ determines the quenching mechanism, that is Cu2+ in the analyte is captured by MOF 1, which has been investigated by ICP, luminescence, UV-vis, XPS, and lifetime studies. Besides, the chemosensor shows regeneration performance without the loss of performance in five consecutive cycles. So MOF 1 is a simple and convenient probe used not only for the rapid detection but also for the enrichment of trace amounts of Cu2+ in aqueous media, and the application can be further extended to a variety of environmental and biological analysis processes.

Study on urinary profile of inborn errors of metabolism by 18-crown-6 modified capillary electrophoresis with laser-induced fluorescence detection.

Newborn screening in urine is important for the diagnosis of many inborn errors of metabolism (IEM). Capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) is a major technological advance in screening IEM. It has the advantage of sensitive and simultaneous multiple disease screening with minimal sample requirement. The analytes were derivatized with fluorescein isothiocyanate (FITC) prior to CE-LIF analysis. In urine samples, free amino acids (AAs) were well separated from other coexisting components, exhibiting a linear calibration over the concentration range 0.01-5.0µmol/L with the limits of detection (LODs) ranging from 0.005 to 0.010µmol/L. The relative standard deviations (RSDs) were in the range 0.1-1.0% for peak area, and 0.2-1.0% for migration time, respectively. Under optimized conditions, the method presented here has been successfully used for the simultaneous and sensitive analysis of seven AAs in urine samples of newborn babies, and evaluating the effect of therapy as well.

Clinical effects of pulse high-volume hemofiltration on severe acute pancreatitis complicated with multiple organ dysfunction syndrome.

To evaluate the effects of pulse high-volume hemofiltration (PHVHF) on severe acute pancreatitis (SAP) with multiple organ dysfunction syndrome (MODS). Thirty patients were divided into two groups: PHVHF group and continuous venovenous hemofiltration (CVVH) group. They were evaluated in terms of clinical symptoms, acute physiology and chronic health evaluation (APACHE) II score, sequential organ failure assessment (SOFA) score, simplified acute physiology (SAPS) II score and biochemical changes. The levels of IL-6, IL-10 and TNF-α in plasma were assessed by ELISA before and after treatment. The doses of dopamine used in shock patients were also analyzed. In the two groups, symptoms were markedly improved after treatment. Body temperature (BT), breath rate (BR), heart rate (HR), APACHE II score, SOFA score, SAPS II score, serum amylase, white blood cell count and C-reactive protein were decreased after hemofiltration (P < 0.05). The PHVHF group was superior to the CVVH group, especially in APACHE II score, CRP (P < 0.01), HR, temperature, SOFA score and SAPS II score (P < 0.05). The doses of dopamine for shock patients were also decreased in the two groups (P < 0.05), with more reduction in the PHVHF group than the CVVH group (P < 0.05). The levels of IL-6, IL-10 and TNF-α decreased (P < 0.05) in the PHVHF group more significantly than the CVVH group (P < 0.01). PHVHF appears to be superior to CVVH in the treatment of SAP with MODS.

Ozone degrades common herbivore-induced plant volatiles: does this affect herbivore prey location by predators and parasitoids?

Inducible terpenes and lipoxygenase pathway products, e.g., green-leaf volatiles (GLVs), are emitted by plants in response to herbivory. They are used by carnivorous arthropods to locate prey. These compounds are highly reactive with atmospheric pollutants. We hypothesized that elevated ozone (O(3)) may affect chemical communication between plants and natural enemies of herbivores by degrading signal compounds. In this study, we have used two tritrophic systems (Brassica oleracea-Plutella xylostella-Cotesia plutellae and Phaseolus lunatus-Tetranychus urticae-Phytoseiulus persimilis) to show that exposure of plants to moderately enhanced atmospheric O(3) levels (60 and 120 nl l(-1)) results in complete degradation of most herbivore-induced terpenes and GLVs, which is congruent with our hypothesis. However, orientation behavior of natural enemies was not disrupted by O(3) exposure in either tritrophic system. Other herbivore-induced volatiles, such as benzyl cyanide, a nitrile in cabbage, and methyl salicylate in lima bean, were not significantly reduced in reactions with O(3). We suggest that more atmospherically stable herbivore-induced volatile compounds can provide important long-distance plant-carnivore signals and may be used by natural enemies of herbivores to orientate in O(3)-polluted environments.