Search

Aquatic organisms in the environment are frequently exposed to a variety of organic chemicals, while these biological species may show different sensitivities to different chemical groups present in the environment. This study evaluated species sensitivity, hazards, and risks of six classes of organic chemicals in the aquatic environment. None of the taxonomic groups were the most sensitive or tolerant to all chemicals, as one group sensitive to one class of chemicals might possess adaptations to other chemical groups. Polychlorinated biphenyls were generally the most toxic chemical group, followed by polybrominated diphenyl ethers, polycyclic aromatic hydrocarbons, and pharmaceuticals and personal care products, while per- and polyfluoroalkyl substances and phthalate esters were the less toxic chemical groups. The hazard of organic chemicals was closely related to their physicochemical properties, including hydrophobicity and molecular weight. It was shown that 20% of the evaluated chemicals exhibited medium or high ecological risks with the worst-case scenario in the Pearl River Estuary. This novel work represented a comprehensive comparison of chemical hazards and species sensitivity among different classes of organic chemicals, and the reported results herein have provided scientific evidence for ecological risk assessment and water quality management to protect aquatic ecosystems against organic chemicals.

In order to effectively achieve the quality classification of sunflower seeds based on appearance identification in production scenarios, a multi-objective sunflower seed classification method based on a self-attention mechanism was proposed in this paper, which achieves the classification of sunflower seed object images with an accuracy of 94.71% by using a Multi-Head Self-attention mechanism to focus on the classification objects on the basis of effectively extracting context-dependent information from sunflower seed images. However, visualization experiments found that the model’s attention could not effectively focus on the class activated regions of the image, resulting in a model that was heavily influenced by background noise and suffered from such defects as high computational cost and large model size. To address the above problems, a self-attention Focusing algorithm was proposed in this paper by evaluating and reconstructing the connections in the attention weight matrix, pruning the less influential connections, and realizing the update of the attention score, which gradually focuses attention on the class activated regions in continuous iterations, effectively shielding the background noise. Experiments have shown that applying the Focusing algorithm improves the accuracy rate to 96.6% based on a 34.3% reduction in the number of model parameters. Model accuracy was successfully improved while achieving model lightweighting, and the model was made more resistant to background noise due to the focused attention region. The self-attention Focusing algorithm’s effectiveness in improving accuracy, focusing attention, and compressing model size is demonstrated. In practical production scenarios, it can be used as a popular application of key techniques for sunflower seed classification.

Coronavirus disease 2019 (COVID-19) is the most serious infectious disease pandemic in the world in a century, and has had a serious impact on the health, safety, and social and economic development of all mankind. Since the earth entered the “Anthropocene”, human activities have become the most important driving force of the evolution of the earth system. At the same time, the epidemic frequency of major human infectious diseases worldwide has been increasing, with more than 70% of novel diseases having zoonotic origins. The review of several major epidemics in human history shows that there is a common rule, i.e., changes in the natural environment have an important and profound impact on the occurrence and development of epidemics. Therefore, the impact of the natural environment on the current COVID-19 pandemic and its mechanisms have become scientific issues that need to be resolved urgently. From the perspective of the natural environment, this study systematically investigated several major issues concerning the environmental transmission and risk prevention of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). From a macroscopic temporal and spatial scale, the research focus on understand the impact of the destruction of the natural environment and global changes on the outbreak of infectious diseases; the threat of zoonotic diseases to human health; the regularity for virus diffusion, migration and mutation in environmental media; the mechanisms of virus transmission from animals and environmental media to humans; and environmental safety, secondary risk prevention and control of major epidemics. Suggestions were made for future key research directions and issues that need attention, with a view to providing a reference for the prevention and control of the global coronavirus disease 2019, and to improving the ability of response to major public health emergencies.

Optimizing and monitoring the growth conditions of Pt films, often used as bottom electrodes in multiferroic material systems, represents a highly relevant issue that is of importance for controlling the crystalline quality and performance of ferroelectric oxides such as, e.g. LuFeO3. We performed a time-resolved monitoring of the growth and morphology of Pt films during pulsed laser deposition (PLD) in dependence on the grown film effective thickness and on the growth temperature Tgusing in situgrazing incidence small-angle X-ray scattering (GISAXS). Through real-time analysis and modeling of GISAXS patterns, we could fully characterize the influence of Tgon the morphology and on the growth kinetics of the Pt layers. Consequently, critical and characteristic effective thicknesses for the transitions nucleation phase (I)/coalescence phase (II) and coalescence phase (II)/coarsening phase (III) could be determined. In combination with complementary microscopic imaging and chemical mapping via combined SEM/EDXS, we demonstrate the occurrence of a morphological progression in the Pt PLD-grown Pt films, changing from grains at room temperature to a 3D-island morphology at 300 °C, further to a hole-free structure at 500 °C, and finally to a channel structure for 700 and 900 °C. The film topography, as characterized by atomic force microscopy (AFM), favors the PLD growth of Pt layers at temperatures beyond 700 °C where the film is homogeneous, continuous, and hole-free with a flat and smooth surface. The double dependency of the percolation transition on the film effective thickness and on the growth temperature has been established by measuring the electrical conductivity.

The large-scale use of organophosphate esters (OPEs) as flame retardants and plasticizers, has led to their prevalence in the surrounding environment, with unknown broader impacts. This study describes the distribution of OPEs in water and soil environments, explores the correlation between their distribution and socioeconomic or climatic characteristics, and assesses the ecological risk of OPEs to aquatic and terrestrial organisms. Our findings showed that socioeconomic characteristics, including the model of industrial development, population density, urbanization, and treatment rate of domestic sewage, play a significant role in driving the distribution of OPEs in surface water and land use. The excessive use of industrial and domestic water directly and indirectly increases the concentrations of OPEs in surface water, and an increase in precipitation can wash out OPEs in the surface soil and allowing them to seep into the groundwater aquifer. OPEs were most prevalent in surface water and land use, but more notable concentrations were also found in farming (∑OPEs: 1.19 ng g−1–1224.61 ng g−1) and construction lands (∑OPEs: 0.8 ng g−1–11,557.83 ng g−1). Based on the risk quotient and risk prioritizing (i.e., expected risk) methods, the ecological risks of OPEs to terrestrial organisms are more sensitive than those on aquatic organisms, particularly for tricresyl phosphate, tris(phenyl) phosphate, tris(2-ethylhexyl) phosphate, tris(2,3-dibromopropyl) phosphate, and 2-ethylhexyl diphenyl phosphate. However, the lack of clear dose–response relationships and toxicological data for most OPEs severely limits their risk assessment. Future research should focus on assessing the impacts of these OPEs on aquatic and terrestrial biodiversity, as well as on strengthening risk management and control.

Cell–cell adhesion complexes are macromolecular adhesive organelles that integrate cells into tissues. This mechanochemical coupling in cell–cell adhesion is required for a large number of cell behaviors, and perturbations of the cell–cell adhesion structure or related mechanotransduction pathways can lead to critical pathological conditions such as skin and heart diseases, arthritis, and cancer. Mechanical stretching has been a widely used method to stimulate the mechanotransduction process originating from the cell–cell adhesion and cell-extracellular matrix (ECM) complexes. These studies aimed to reveal the biophysical processes governing cell proliferation, wound healing, gene expression regulation, and cell differentiation in various tissues, including cardiac, muscle, vascular, and bone. This review explores techniques in mechanical stretching in two-dimensional settings with different stretching regimens on different cell types. The mechanotransduction responses from these different cell types will be discussed with an emphasis on their biophysical transformations during mechanical stretching and the cross talk between the cell–cell and cell-ECM adhesion complexes. Therapeutic aspects of mechanical stretching are reviewed considering these cellular responses after the application of mechanical forces, with a focus on wound healing and tissue regeneration.Impact StatementMechanical stretching has been proposed as a therapeutic option for tissue regeneration and wound healing. It has been accepted that mechanotransduction processes elicited by mechanical stretching govern cellular response and behavior, and these studies have predominantly focused on the cell-extracellular matrix (ECM) sites. This review serves the mechanobiology community by shifting the focus of mechanical stretching effects from cell-ECM adhesions to the less examined cell–cell adhesions, which we believe play an equally important role in orchestrating the response pathways.

Metals can pose hazards to marine species and can adversely affect structures and functions of communities of marine species. However, little is known about how structural properties of metal atoms combined with current geographical and climatic conditions affect their toxic potencies. A mathematical model, based on quantitative structure–activity relationships and species sensitivity distributions (QSAR-SSD) was developed by use of acute toxicities of six metals (Cd, Cr, Cu, Hg, Ni, and Zn) to eight marine species and accessory environmental conditions. The model was then used to predict toxicities of 31 metals and metalloids and then to investigate relationships between acute water quality criteria (WQC) and environmental conditions in coastal marine environments. The model was also used to predict WQC in the coastal areas of different countries. Given global climate change, the QSAR-SSD model allows development of WQC for metals that will be protective of marine ecosystems under various conditions related to changes in global climate. This approach could be of enormous benefit in delivering an evidence-based approach to support regulatory decision making in management of metal and metalloids in marine waters.

We have studied the effect of platinum underlayer for two deposited thicknesses on the microstructure, crystalline quality, morphology, chemical composition, and magnetic properties as well as magnetic domain formation of BaFe12O19(BaM) grown on YSZ(111) by pulsed laser deposition (PLD). We found that PLD platinum deposited with a thickness of 25 nm cannot withstand the dewetting phenomenon occurring during the subsequent BaM layer growth. A smooth and continuous Pt underlayer that possesses a sharp interface and omits the intermixing between the BaM and substrate was successfully achieved for a deposited Pt film thickness of 75 nm. Independent of the thickness of the deposited Pt layer, the c-axis orientation as well as coercivity Hc and the anisotropy HAfields were significantly improved due to a remarkable improvement of lattice mismatch in comparison with the BaM layer grown without a Pt underlayer on YSZ(111). By applying high-resolution X-ray diffraction, scanning and transmission electron microscopy (SEM/TEM), and atomically resolved scanning TEM imaging combined with energy-dispersive X-ray spectroscopy, as well as atomic and magnetic force microscopy, a comprehensive investigation of both structure and chemical composition of the deposited BaM films and their interfacial regions was performed. This study aimed to correlate the enhancement of the overall magnetic properties and of the local spin magnetic domain orientation with the modification of BaM microstructure and chemical composition at the nanometer scale due to the Pt underlayer. Finally, we attempted to understand the mechanisms that control the magnetic properties of these BaM films in order to be able to tailor them.

The objective of this research is to improve the strength characteristics of red clay as a subgrade filler and increase the stability of subgrade engineering. During the laboratory tests, different amounts of waste tire rubber powder were added to the red clay. This study aims to identify the optimal amount of rubber powder required to improve the strength characteristics of red clay using a triaxial test and Duncan–Chang model. Using the depth of a field microscope, the apparent morphology of red clay and modified red clay was analyzed, and the pore variation of plain red clay and rubber powder modified red clay was described using a mercury intrusion test(MIP). The experimental results indicate that the asymptotic value of the main stress difference is significantly higher than the other four admixtures at 3%. The 3D surface comparison chart indicates that the addition of rubber powder significantly increases the relatively flat area range while reducing the overall area range. According to the comparison of porosity and contact area ratio, RPA1is larger than RPA2, and RCA1is smaller than RCA2. According to the characteristics of BJH pore size distribution, modified red clay has a higher pore fractal dimension than pure red clay.

With their capability to undergo unlimited self-renew and to differentiate into various functional cells, human pluripotent stem cells, including embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs), hold great promise in regenerative medicine to treat currently incurable diseases. Significant progress has been achieved in differentiating pluripotent stem cells into various functional cells, such as pancreatic β cells, neural cells, hepatocytes, and cardiomyocytes. In addition, three hESC-based therapies to treat spinal cord injury, macular degeneration and type 1 diabetes have entered clinical trial. However, there remain several major bottlenecks that hinder the clinical trial of stem cell based therapy. One such key challenge is the immune rejection of cells derived from allogeneic hESCs. The challenge of immune rejection is mitigated by recent discovery of iPSCs, raising the hope that patient-specific hiPSCs can be differentiated into autologous cells for transplantation into the same patient without the concern of immune rejection. However, due to the oncogenic potential of the reprogramming factors and the reprogramming- induced DNA damage, there remain safety concerns about the cancer risk and immunogenicity of hiPSC-derived cells. This review discusses recent progress in our understanding of the immunogenicity of pluripotent stem cells and the development of new strategies to resolve this challenge.

•A machine learning based non-iterative solver for PPE is developed.•An ML-block is used to completely or partially replace the traditional iterative solver.•The participation of ML-block speeds up the solution of the Navier-Stokes equations.

Monitoring of status and trends of quality of surface waters is important to assure sustainability of desired structures and functions of aquatic environments. Recently, several sets of legislation worldwide (USA, European Commission, Canada, Australia, South Africa, etc.) have been developed, that consider water bodies as ecological systems, in order to address ecological quality or integrity of watersheds. Current monitoring and assessment of water quality in China, which is still based on amounts of chemical pollutants, such as ammonia and BOD, has been deemed to be insufficient to adequately assess the quality of aquatic environments. Responding to this challenge, China has embarked on a pilot national monitoring program to assess ecological integrities of major watersheds beginning in 2010. The components used in this monitoring and assessment system include hydrology, river morphology, physico-chemical parameters, ecotoxicological aspects, types and numbers of biota and age and growth of fishes. Based on the results of the pilot scheme an ecological integrity index for surface waters will be established; a national coordination and management system, including methods for comprehensive monitoring of ecological integrity of surface waters in China will be initiated.

Novel tricyclic imidazoline antagonists of the adenosine A1receptor are described. For key compounds, the selectivity level over other adenosine receptor subtypes is examined along with their in vivo effects in a rat diuresis model. Compound 14, the (R)-isomer of 7,8-dihydro-8-ethyl-2-(4-bicyclo2.2.2octan-1-ol)-4-propyl-1H-imidazo2,1-ipurin-5(4H)-one, is a particularly potent adenosine A1receptor antagonist with good selectivity over the other three adenosine receptor subtypes:? A1(human) Ki 22 nM; A2A(human) Ki 4400 nM; A2B(human) Ki 580 nM; A3(human) Ki= 10?000 nM. Imidazoline 14is a competitive adenosine A1receptor antagonist with a pA2value of 8.88 and is highly soluble in water (>100 mg/mL). In addition, it has an oral bioavailability of 84% and an oral half-life of 3.8 h in rats. When orally administered in a rat diuresis model, compound 14promoted sodium excretion (ED50 0.01 mg/kg). This level of efficacy is comparable to that of BG9928, a selective adenosine A1receptor antagonist that is currently in clinical trials as a treatment for congestive heart failure. Additional modifications to 14also showed that the bridgehead hydroxyl group could be replaced with a propionic acid (compound 36) without a significant loss in binding affinity or in vivo activity.

In the search for a selective adenosine A1receptor antagonist with greater aqueous solubility than the compounds currently in clinical trials as diuretics, a series of 1,4-substituted 8-cyclohexyl and 8-bicyclo2.2.2octylxanthines were investigated. The binding affinities of a variety of cyclohexyl and bicyclo2.2.2octylxanthines for the rat and human adenosine A1, A2A, A2B, and A3receptors are presented. Bicyclo2.2.2octylxanthine 16exhibited good pharmaceutical properties and in vivo activity in a rat diuresis model (ED50 0.3 mg/kg po). Optimization of the bridgehead substituent led to propionic acid 29(BG9928), which retained high potency (hA1, Ki 7 nM) and selectivity for the adenosine A1receptor (915-fold versus adenosine A2Areceptor; 12-fold versus adenosine A2Breceptor) with improved oral efficacy in the rat diuresis model (ED50 0.01 mg/kg) as well as high oral bioavailability in rat, dog, and cynomolgus monkey.

Stimulation of A1adenosine receptors in the kidney reduces glomerular filtration rate (GFR) via tubuloglomerular feedback and increases sodium reabsorption. Blocking A1adenosine receptors would therefore maintain GFR and cause natriuresis. These attributes would be especially beneficial in treating congestive heart failure (CHF). BG9928 is a xanthine derivative that binds with high affinity to A1adenosine receptors from several species including human and acts as a competitive antagonist at these receptors. This compound is being developed for the treatment of CHF. BG9928 receptor binding across a wide array of human and animal receptors was evaluated in vitro. Oral dose–response was assessed in rats, and oral and iv dose–responses were assessed in monkeys. The functional potency of BG9928 was demonstrated in vivo in rats. The binding affinity (Ki) for the human A1adenosine receptor is 12.2 nM. BG9928 is orally active, with a dose of 0.3 mg/kg po achieving full natriuretic response in rats and with iv doses as low as 0.03 mg/kg showing activity in nonhuman primates. The renal protective effects of BG9928 were demonstrated by coadministration with the loop diuretic furosemide. In rats, administration of BG9928 effectively attenuated the reductions in GFR that usually occur with the administration of furosemide. Blockade of A1receptors by BG9928 protects renal function against the adverse effects of loop diuretics and exerts additive natriuretic effects. In CHF patients, this profile may translate into significant clinical benefit by enhancing natriuresis with diminished concern of inducing renal insufficiency. Drug Dev. Res. 58:486–492, 2003. © 2003 Wiley‐Liss, Inc.

Stimulation of A1adenosine receptors in the kidney reduces glomerular filtration rate (GFR) via tubuloglomerular feedback and increases sodium reabsorption. Blocking A1 adenosine receptors would therefore maintain GFR and cause natriuresis. These attributes would be especially beneficial in treating congestive heart failure (CHF). BG9928 is a xanthine derivative that binds with high affinity to A1 adenosine receptors from several species including human and acts as a competitive antagonist at these receptors. This compound is being developed for the treatment of CHF. BG9928 receptor binding across a wide array of human and animal receptors was evaluated in vitro. Oral dose–response was assessed in rats, and oral and iv dose–responses were assessed in monkeys. The functional potency of BG9928 was demonstrated in vivo in rats. The binding affinity (Ki) for the human A1 adenosine receptor is 12.2 nM. BG9928 is orally active, with a dose of 0.3 mg/kg po achieving full natriuretic response in rats and with iv doses as low as 0.03 mg/kg showing activity in nonhuman primates. The renal protective effects of BG9928 were demonstrated by coadministration with the loop diuretic furosemide. In rats, administration of BG9928 effectively attenuated the reductions in GFR that usually occur with the administration of furosemide. Blockade of A1 receptors by BG9928 protects renal function against the adverse effects of loop diuretics and exerts additive natriuretic effects. In CHF patients, this profile may translate into significant clinical benefit by enhancing natriuresis with diminished concern of inducing renal insufficiency. Drug Dev. Res. 58:486–492, 2003. © 2003 Wiley-Liss, Inc.

The role of mPer1and mPer2in regulating circadian rhythms was assessed by disrupting these genes. Mice homozygous for the targeted allele of either mPer1or mPer2had severely disrupted locomotor activity rhythms during extended exposure to constant darkness. Clock gene RNA rhythms were blunted in the suprachiasmatic nucleus of mPer2mutant mice, but not of mPER1-deficient mice. Peak mPER and mCRY1 protein levels were reduced in both lines. Behavioral rhythms of mPer1/mPer3and mPer2/mPer3double-mutant mice resembled rhythms of mice with disruption of mPer1or mPer2alone, respectively, confirming the placement of mPer3outside the core circadian clockwork. In contrast, mPer1/mPer2double-mutant mice were immediately arrhythmic. Thus, mPER1 influences rhythmicity primarily through interaction with other clock proteins, while mPER2 positively regulates rhythmic gene expression, and there is partial compensation between products of these two genes.

ABSTRACTNeurons in the mammalian suprachiasmatic nucleus (SCN) contain a cell-autonomous circadian clock that is based on a transcriptional-translational feedback loop. The basic helix-loop-helix–PAS proteins CLOCK and BMAL1 are positive regulators and drive the expression of the negative regulators CRY1 and CRY2, as well as PER1, PER2, and PER3. To assess the role of mouse PER3 (mPER3) in the circadian timing system, we generated mice with a targeted disruption of the mPer3gene. Western blot analysis confirmed the absence of mPER3-immunoreactive proteins in mice homozygous for the targeted allele. mPer1,mPer2, mCry1, and Bmal1RNA rhythms in the SCN did not differ between mPER3-deficient and wild-type mice. Rhythmic expression of mPer1and mPer2RNAs in skeletal muscle also did not differ between mPER3-deficient and wild-type mice. mPer3transcripts were rhythmically expressed in the SCN and skeletal muscle of mice homozygous for the targeted allele, but the level of expression of the mutant transcript was lower than that in wild-type controls. Locomotor activity rhythms in mPER3-deficient mice were grossly normal, but the circadian cycle length was significantly (0.5 h) shorter than that in controls. The results demonstrate that mPer3is not necessary for circadian rhythms in mice.

Neurons in the mammalian suprachiasmatic nucleus (SCN) contain a cell-autonomous circadian clock that is based on a transcriptional-translational feedback loop. The basic helix-loop-helix–PAS proteins CLOCK and BMAL1 are positive regulators and drive the expression of the negative regulators CRY1 and CRY2, as well as PER1, PER2, and PER3. To assess the role of mouse PER3 (mPER3) in the circadian timing system, we generated mice with a targeted disruption of the mPer3gene. Western blot analysis confirmed the absence of mPER3-immunoreactive proteins in mice homozygous for the targeted allele. mPer1,mPer2, mCry1, and Bmal1RNA rhythms in the SCN did not differ between mPER3-deficient and wild-type mice. Rhythmic expression of mPer1and mPer2RNAs in skeletal muscle also did not differ between mPER3-deficient and wild-type mice. mPer3transcripts were rhythmically expressed in the SCN and skeletal muscle of mice homozygous for the targeted allele, but the level of expression of the mutant transcript was lower than that in wild-type controls. Locomotor activity rhythms in mPER3-deficient mice were grossly normal, but the circadian cycle length was significantly (0.5 h) shorter than that in controls. The results demonstrate that mPer3is not necessary for circadian rhythms in mice.

We cloned the mouse cDNA of a mammalian homolog of the Drosophila timeless(tim) gene and designated it mTim. The mTimprotein shows five homologous regions with DrosophilaTIM. mTimis weakly expressed in the suprachiasmatic nuclei (SCN) but exhibits robust expression in the hypophyseal pars tuberalis (PT). mTimRNA levels do not oscillate in the SCN nor are they acutely altered by light exposure during subjective night. mTimRNA is expressed at low levels in several peripheral tissues, including eyes, and is heavily expressed in spleen and testis. Yeast two-hybrid assays revealed an array of interactions between the various mPER proteins but no mPER–mTIM interactions. The data suggest that PER–PER interactions have replaced the function of PER–TIM dimers in the molecular workings of the mammalian circadian clock.

Sulphurization processes in Cu(In,Ga)Se2thin-film solar cells has been intensively studied in the last decade as a viable alternative to the existing Ga-grading. The main advantage of using S grading is that by substituting Se with S we will achieve not only an upshift of the conduction-band minimum as done by employing Ga grading, but also a downshift of the valence-band maximum. Several existing studies stipulate that S is very often inserted in too high concentrations into Cu(In,Ga)Se2absorber by sulphurization resulting in a deteriorated device performance instead of the expected beneficial effect. However, we demonstrate here that the intense sulphurization process when accompanied by Ga-grading leads to improved electrical properties of the buffer/absorber heterojunction. More exactly, this double grading at the absorber surface leads to strong reduction of the p-doping and hence to a change in the band diagram. This work also proves that the intense sulphurization process is accompanied by strong structural and chemical changes, i.e. by the formation of a S-rich CuIn(S,Se)2compound at the absorber surface. Finally, all these experimental findings were complemented by ab-initiocalculations of the conduction-band and valence-band offsets between absorber and buffer obtained by using density functional theory. Hence, the present work opens up new possibilities for synthesizing Cu(In,Ga)(Se,S)2solar cells with superior cell performance when using an intense sulphurization process.

The article discusses the proposal of using a wavelet network principle in formulating models for predicting elevator traffic-flow. The Fleteter-Reeves conjugate-gradient method is used to make network training and weight adjust. According to the author, the results of the analog simulation show that the method is superior compared with the traditional BP neural network method. Moreover, the traffic-flow prediction model can also apply to other than office buildings.

Photoisomerization from cis-2 [Ru(OAc)(2cqn)2NO] (H2cqn=2-chloro-8-quinolinol) to cis-1 isomer was studied quantitatively and the effect of wavelength on isomerization was investigated. The main absorption band in UV-Vis region for cis-1 and cis-2 isomer was observed from 350 nm to 500 nm, and the kinetic study showed that the photoisomerization from cis-2 to cis-1 isomer was first-order and the rate constant (k) is 0.00022 (s-1) at 420 nm, 0.00018 (s-1) at 475 nm, 0.00011 (s-1) at 550 nm, respectively. Density functional theory (DFT) calculation suggested that the electronic transition from a ligand based orbital to an antibonding overlap of the Ru(d) and * NO(p)orbitals control the photo induced reactivity of [Ru(OAc)(2cqn)2NO] complexes. The study provides basic information to design the molecular optical switches and advance optoelectronic materials based on nitrosylruthenium(II) complexes.