Quantitative characterization of tumor cell traction force on extracellular matrix by hydrogel microsphere stress sensor.

Cell traction force (CTF) is a kind of active force that is a cell senses external environment and actively applies to the contact matrix which is currently a representative stress in cell-extracellular matrix (ECM) interaction. Studying the distribution and variation of CTF during cell-ECM interaction help to explain the impact of physical factors on cell behaviors from the perspective of mechanobiology. However, most of the strategies of characterizing CTF are still limited by the measurement needs in three-dimensional (3D), quantitative characteristics and in vivo condition. Microsphere stress sensor (MSS) as a new type of technology is capable of realizing the quantitative characterization of CTF in 3D and in vivo. Herein, we employed microfluidic platform to design and fabricate MSS which possesses adjustable fluorescent performances, physical properties, and size ranges for better applicable to different cells (3T3, A549). Focusing on the common tumor cells behaviors (adhesion, spreading, and migration) in the process of metastasis, we chose SH-SY5Y as the representative research object in this work. We calculated CTF with the profile and distribution to demonstrate that the normal and shear stress can determined different cell behaviors. Additionally, CTF can also regulate cell adhesion, spreading, and migration in different cell states. Based on this method, the quantitative characterization of CFT of health and disease cells can be achieved, which further help to study and explore the potential mechanism of cell-ECM interaction.

A review of neuroendocrine immune system abnormalities in IBS based on the brain-gut axis and research progress of acupuncture intervention.

Irritable bowel syndrome (IBS) is a common digestive disorder observed in clinics. Current studies suggest that the pathogenesis of the disease is closely related to abnormal brain-gut interactions, hypokinesia, visceral sensory hypersensitivity in the gastrointestinal tract, and alterations in the intestinal microenvironment. However, it is difficult for a single factor to explain the heterogeneity of symptoms. The Rome IV criteria emphasized the holistic biologic-psycho-social model of IBS, suggesting that symptoms of the disease are closely related to neurogastroenterology and various abnormalities in brain-gut interaction. This study comprehensively reviewed the relationship between the brain-gut axis and IBS, the structure of the brain-gut axis, and the relationship between the brain-gut axis and intestinal microenvironment, and discussed the relationship between the abnormal regulation of the nervous system, endocrine system, and immune system and the incidence of IBS on the basis of brain-gut axis. In terms of treatment, acupuncture therapy can regulate the neuroendocrine-immune system of the body and improve the intestinal microenvironment, and it has the advantages of safety, economy, and effectiveness. We study the pathogenesis of IBS from local to global and micro to macro, and review the use of acupuncture to treat the disease as a whole so as to provide new ideas for the treatment of the disease.

Efficacy of moxibustion in diarrhea-predominant irritable bowel syndrome model rats: a systematic review and meta-analysis.

Objective: To systematically evaluate the efficacy of moxibustion in diarrhea-predominant irritable bowel syndrome (IBS-D) model rats. Methods: A comprehensive search was conducted in the China National Knowledge Infrastructure, WanFang Data, VIP, PubMed, Embase, and Web of Science databases from their inception to June 30, 2023. Relevant animal experiments investigating moxibustion for treating IBS-D in model rats were included. Two independent researchers screened the literature, extracted data, and evaluated the risk of bias in the selected studies. The meta-analysis was performed using RevMan 5.3 software. Results: In total, 21 animal studies comprising 680 model rats were included. The meta-analysis results demonstrated that moxibustion enhanced the threshold capacity of the abdominal withdrawal reflex (AWR) [standardized mean difference (SMD) = 1.84; 95% confidence interval (CI): 1.09, 2.60; p < 0.00001], ameliorated the rate of loose stool (SMD = -4.03; 95% CI: -5.76, -2.30; p < 0.00001), and decreased the colon 5-hydroxytryptamine (SMD = -3.67; 95% CI: -5.33, -2.01; p < 0.00001), serum interleukin-1ß (SMD = -3.24, 95% CI: -4.06, -2.41; p < 0.00001), serum tumor necrosis factor-α (SMD = -2.35, 95% CI: -4.12, -0.58; p < 0.00001), and serum substance P (SMD = -5.14, 95% CI: -8.45, -1.83; p = 0.002) concentrations. Moxibustion did not affect the blood calcitonin gene-related peptide level compared to the blank model group (p = 0.15). Conclusion: Moxibustion modulated the brain-gut interaction, reduced visceral hypersensitivity, inhibited intestinal inflammation, and regulated the immune balance, improving the rate of loose stool and increasing the AWR threshold capacity in IBS-D model rats, achieving good analgesic and antidiarrheal effects. However, these conclusions require further validation due to limitations in the quantity and quality of the included studies.

Numerical Analysis of Fiber/Air-Coupling Field for Annular Jet.

Melt-blowing technology is an important method for directly preparing micro-nanofiber materials by drawing polymer melts with high temperature and high velocity air flow. During the drawing process, the melt-blowing fiber not only undergoes a phase change, but also has an extremely complex coupling effect with the drawing airflow. Therefore, in the numerical calculation of the flow field, the existence of melt-blowing fibers is often ignored. In this paper, based on the volume of fluid method, a numerical study of the flexible fiber/air-coupling flow field of an annular melt-blowing die is carried out with the aid of computational fluid dynamics software. The results show that the pressure distribution in the different central symmetry planes of the ring die at the same time was basically the same. However, the velocity distribution may have been different; the velocity on the spinning line varied with time; the pressure changes on the spinning line were small; and velocity fluctuations around the spinning line could cause whiplash of the fibers.

Guanidyl-implanted UiO-66 as an efficient catalyst for the enhanced conversion of carbon dioxide into cyclic carbonates.

The development of heterogeneous catalysts for promoting epoxide cycloaddition with carbon dioxide is highly desirable for recycling CO2 and achieving the goal of carbon neutrality. Herein, we designed and synthesized Zr-based metal organic frameworks (MOFs) by implanting functional guanidyl into the framework via mixing different molar ratios of 4-guanidinobenzoic acid (Gua) with 1,4-benzenedicarboxylic acid (BDC). Consequently, a small sized Zr-MOF (∼350 nm) can be prepared by implanting Gua with 20% molar ligands, denoted as UiO-66-Gua0.2(s). Compared to large sized and different guanidyl Zr-MOFs, UiO-66-Gua0.2(s) exhibited an optimal activity on catalyzing epoxide cycloaddition with CO2 in the presence of the Bu4NBr cocatalyst. A yield of 97% for the product of chloropropene carbonate was achieved at 90 °C under 1 atm CO2. The great performance of UiO-66-Gua0.2(s) might be attributed to the synergistic effect of guanidyl groups as hydrogen-bond donors and Zr centers acting as Lewis-acidic sites. In addition, the heterogeneous catalyst of UiO-66-Gua0.2(s) exhibited a great versatility towards converting other epoxides and a satisfactory recyclability for five consecutive runs. Moreover, a plausible reaction mechanism has been proposed for UiO-66-Gua0.2(s) in promoting CO2 epoxide cycloaddition reactions.

A Comparison Study of the Effect on IBS-D Rats among Ginger-Partitioned Moxibustion, Mild Moxibustion, and Laser Moxibustion.

BACKGROUND: Diarrhea-predominant irritable bowel syndrome (IBS-D) is a functional gastrointestinal disorder that severely affects patients' life. Moxibustion is believed to be an effective way to treat IBS-D. However, the therapeutic effects and the underlying mechanisms in symptom management of IBS-D by different moxibustion therapies remain unclear. METHODS: IBS-D model rats were divided into groups and treated with ginger-partitioned moxibustion (GPM), mild moxibustion (MM), and laser moxibustion (LM) at a temperature of 43°C, respectively. The temperature curves of acupoints were recorded during interventions. The therapeutic effects were evaluated on the basis of general condition, stool, and hematoxylin-eosin staining of the colon tissue. Moreover, the expression of transient receptor potential vanilloid 1 (TRPV1) receptors in both acupoint tissue and colon tissue was analyzed by immunohistochemistry. RESULTS: After moxibustion treatment, the symptoms were improved. The expression of TRPV1 was increased in acupoint tissue and decreased in colon tissue. GPM and MM showed a more significant influence on IBS-D rats compared with LM. The temperature profile of GPM and MM was wave-like, while LM had an almost stable temperature curve. CONCLUSION: GPM, MM, and LM could improve the symptoms in IBS-D rats. Moxibustion might activate TRPV1 channels in the acupoint tissue and induce acupoint functions, which in turn inhibit the pathological activation state of the colon's TRPV1, followed by improvements in abdominal pain and diarrheal symptoms. LM with stable temperature might lead to the desensitization of TRPV1 receptors and the tolerance of acupoint. GPM and MM provided dynamic and repetitive thermal stimulations that perhaps induced acupoint sensitization to increase efficacy. Therefore, dynamic and repetitive thermal stimulation is recommended in the application of moxibustion.

Dye-sensitized core-shell NaGdF4:Yb,Er@NaGdF4:Yb,Nd upconversion nanoprobe for determination of H2S.

The core-shell NaGdF4:Yb,Er@NaGdF4:Yb,Nd upconversion nanoparticles (UCNPs) were successfully obtained with the method of co-precipitation, and the water-solubility of UCNPs was improved by the ligand exchange reaction between nitrosyl tetrafluoroborate (NOBF4) and nanoparticles. The IR-783 dye with negative charge and NOBF4-UCNPs with positive charge can bind together by electrostatic action to sensitize UCNPs through the energy transfer from IR-783 to UCNPs. However, with the presence of Na2S (a commonly used H2S donor), a highly selective reaction between H2S and IR-783, which destoried the structure of IR-783 and blocked the energy transfer, thus led to the quenching of luminescent intensity. Based on this, a sensing system for determination of H2S has been constructed successfully. The linear range of H2S detection by this system is 0.5-15 µM, and the detection limit is 34.17 nM. Furthermore, the dye-sensitized core-shell NaGdF4:Yb,Er@NaGdF4:Yb,Nd upconversion nanoprobe was applied to real sample analysis with satisfactory results.

Molybdenum Carbide-Embedded Multichannel Hollow Carbon Nanofibers as Bifunctional Catalysts for Water Splitting.

With the environmental pollution and non-renewable fossil fuels, it is imperative to develop eco-friendly, renewable, and highly efficient electrocatalysts for sustainable energy. Herein, a simple electrospinning process used to synthesis Mo2 C-embedded multichannel hollow carbon nanofibers (Mo2 C-MCNFs) and followed by the pyrolysis process. As prepared lotus root-like nanoarchitecture could offer rich porosity and facilitate the electrolyte infiltration, the Mo2 C-MCNFs delivered favourable catalytic activity for HER and OER. The resultant catalysts exhibit low overpotentials of 114 mV and 320 mV at a current density of 10 mA cm-2 for HER and OER, respectively. Furthermore, using the Mo2 C-MCNFs catalysts as a bifunctional electrode toward overall water splitting, which only needs a small cell voltage of 1.68 V to afford a current density of 10 mA cm-2 in the home-made alkaline electrolyzer. This interesting work presents a simple and effective strategy to further fabricating tunable nanostructures for energy-related applications.

The thermal performance of biological tissue under moxibustion therapy.

An understanding of the thermal performance of biological tissue under moxibustion with ash cleaning and distance adjustment (ACDA) is helpful for the optimization and standardization of moxibustion clinical treatment. This study compared surface temperature distribution of burning moxa stick with and without ash cleaning. The experimental of moxibustion treatment on in-vitro tissue and human abdomen were conducted and corresponding numerical models were developed. The effect of ACDA on thermal performance of biological tissue under moxibustion therapy were analyzed. The results show that the surface temperature of burning moxa stick with ash cleaning maintained at a higher range compared to that without ash cleaning. During moxibustion with ACDA process in in-vitro tissue experiment, the temperature increase (ΔT) at skin surface almost fluctuated in the same temperature range, and the ΔT in subcutaneous tissue (>11 mm) kept increasing. Relatively, these ΔT under moxibustion treatment without ACDA showed different trends and these values were all much smaller than those with ACDA. In addition, the position of maximum temperature of tissue under moxibustion with and without ACDA was fixed on treatment acupoint and moved away from treatment acupoint, respectively. Besides, the surface temperature of human abdomen tissue under moxibustion treatment with ACDA can be maintained at 46 °C-50 °C for a longer time compared to that under moxbustion without ACDA. In conclusion, moxibustion with ACDA can create a larger and more durable thermal effect on biological tissue. The results also suggest that ACDA may be helpful to improve moxibustion therapy efficacy in clinic treatments.

The Effect of Moxibustion Stimulation on Local and Distal Skin Temperature in Healthy Subjects.

The aim of this study is to investigate the response of local and distal skin temperature to moxibustion stimulation (MS) and explore the effects of MS on sympathetic nerve activity. The distal skin temperatures of fingertips, as an indicator for sympathetic reflex response, were recorded using infrared camera during resting period (10 min), MS period (10 min), and natural cooling period (15 min), respectively. The MS without ash cleaning (AC) was applied to acupoints Quze (PC3) (Group I) and Lao Gong (PC8) (Group II), respectively. In Group III, the MS with the operation of AC was performed on PC8. The temperature responses of the local stimulation points and corresponding control points were also investigated. At the beginning of MS period, a significant increase of temperature on the stimulation point accompanied by a simultaneous reduction of temperature on fingertips was observed. A marked negative correlation was also obtained between temperature changes in the stimulation point and in the fingertips. At the end of natural cooling period (t = 34 min), the temperature of stimulation point was obviously higher than baseline values. In contrast, the temperatures of fingertips increased and then returned to the baseline levels during the second minute of MS period. In Group III, the temperature of stimulation point increased every time with the operation of AC, accompanied by the temperature decrease of middle fingertip. The findings suggest that moxibustion may trigger the sympathetic nervous system and induce the reduction of microcirculation, accompanied by a reduction of fingertip temperature. In addition, the operation of AC caused repeated cycles of thermal stimulation on the stimulation point, which may repetitively activate cutaneous sympathetic nerve fibres and evoke the temperature reduction of fingertips.

The protective effects of acupoint gel embedding on rats with myocardial ischemia-reperfusion injury.

AIMS: Prevention and treatment of myocardial ischemia-reperfusion (I/R) injury has for many years been a hot topic in treating ischemic heart disease. As one of the most well-known methods of complementary and alternative medicine, acupuncture has attracted increasing interest in preventing myocardial I/R injury due to its remarkable effectiveness and minimal side effect. However, traditional acupuncture approaches are limited by cumbersome execution, high labor costs and inevitable pain caused by frequent stimulation. Therefore, in this work, we aimed to develop a novel acupoint gel embedding approach and investigated its role in protecting against myocardial I/R injury in rats. MAIN METHODS: Gels were embedded at bilateral Neiguan (PC6) points of rats and their protective effects against myocardial I/R injury evaluated in terms of changes in histomorphology, myocardial enzymology, antioxidant capacity, anti-inflammatory response, and anti-apoptosis of cells. KEY FINDINGS: We found that the approach of acupoint gel embedding could significantly reduce myocardial infarcted size, repair pathological changes, mitigate oxidative stress damage and inflammatory response, as well as inhibit apoptosis of cardiomyocytes. Such cardioprotective effects were found to be associated with Notch-1/Jagged-1 signaling pathway. SIGNIFICANCE: The proposed approach of acupoint gel embedding has advantages in continuous acupoint stimulation, dosing controls, and no side effects in the course of treatment, as well as in reducing the pain caused by frequent acupuncture. It can form an alternative therapy to not only protect against myocardial I/R injury but also hold great potential in treating other diseases in the future.

Droplet based vitrification for cell aggregates: Numerical analysis.

Cell aggregates represent the main format of cells existing in vivo and have been widely used as tissue and disease models in vitro. Nevertheless, the preservation of cell aggregates while maintaining their functionalities for off-the-shelf applications is still challenging. Among various preservation methods, droplet-based vitrification exhibits superior advantages for the cryopreservation of cell aggregates; however, the physical mechanisms underlying droplet-based vitrification of cell aggregate using this method remain elusive. To address this issue, we proposed a voronoi model to construct two-dimensional geometric morphologies of cell aggregates and established a coupled physical model to describe the diffusion, heat transfer and crystallization processes during vitrification. Based on these models, we performed a numerical study on the variation and distribution of cryoprotectant (CPA) concentration, temperature and crystallization in cell aggregates during droplet-based vitrification. The results show that although cell membrane is not an obvious barrier in heat transfer, it affects the diffusion of CPA remarkably as a biologic film and thus the following crystallization in cell aggregates. The effective protection of CPA during vitrification occurs during the initial stage of CPA diffusion, thus a longer CPA loading time does not necessarily lead to significant decrease in crystallization, but rather may induce more toxicity to cells.

An In Vitro and Numerical Study of Moxibustion Therapy on Biological Tissue.

OBJECTIVE: Moxibustion therapy achieves satisfactory therapeutic effects largely depending on the heat stimulation of burning moxa. Understanding the thermal characteristics of heating process is an effective way to reveal the underlying mechanisms of moxibustion therapy. METHODS: This paper performs experimental study on temperature distributions of burning moxa sticks and fresh in vitro porcine abdominal tissue using an infrared camera and thermocouples. Meanwhile, a moxibustion model incorporating moxa stick burning model and tissue heat transfer model was established with consideration of radiation propagation and water evaporation. RESULTS: The burning features of moxa sticks were acquired and the radiation energy generated by the burning moxa stick was absorbed and scattered in biological tissue, resulting in a large temperature gradient in the skin layer. And the water evaporation led to a mass loss and reduced skin surface temperature. The numerical model was verified by experimental results and the effects of moxibustion treatment distance and duration can be quantified based on model calculation. CONCLUSION: The detailed heat transfer process of moxibustion was obtained experimentally and numerically. During moxibustion, the radiation attenuation and water evaporation have a significant influence on the energy transport in biological tissue which cannot be ignored. The treatment distance of 3 cm is the recommended value to achieve the treatment efficacy without thermal damage and pain. SIGNIFICANCE: This research would reveal the underlying mechanisms of moxibustion therapy. Besides, the developed models are expected to establish a guideline for moxibustion clinical treatment.

Non-invasive tracking of hydrogel degradation using upconversion nanoparticles.

Tracking the distribution and degradation of hydrogels in vivo is important for various applications including tissue engineering and drug delivery. Among various imaging modalities, fluorescence imaging has attracted intensive attention due to their high sensitivity, low cost and easy operation. Particularly, upconversion nanoparticles (UCNPs) that emit visible lights upon near-infrared (NIR) light excitation as tracking probes are promising in deciphering the fate of hydrogels after transplantation. Herein, we reported a facile and non-invasive in vivo hydrogel tracking method using UCNPs, where the degradation of hydrogels was determined using the decrease in fluorescence intensity from the UCNPs encapsulated in the hydrogels. We found that the change in the fluorescence intensity from the UCNPs was well consistent with that of the fluorescein isothiocyanate (FITC) covalently conjugated to hydrogels and also with the weight change of the hydrogels, suggesting the accuracy of the UCNPs in tracking the degradation of hydrogels. Furthermore, the in vivo fluorescence signals were only observed from the UCNPs instead of FITC after implantation for 7days due to the deep tissue penetration of UCNPs, demonstrating the capability of UCNPs in longitudinal, consecutive and non-invasive monitoring the in vivo degradation of hydrogels without causing any damage to the major organs (heart, lung, liver and kidney) of model rats. This study thus paves the way for monitoring the in vivo behaviors of biomimetic materials via deep tissue imaging with great clinical translation potentials. STATEMENT OF SIGNIFICANCE: Long-term noninvasive in vivo tracking of the distribution and degradation of biodegradable hydrogels using fluorescent probes is important in tissue regeneration and drug delivery. Unlike the widely used fluorescent dyes and quantum dots (QDs) that suffer from photobleaching and undesired toxicity, upconversion nanoparticles (UCNPs) with high stability, deep tissue penetration as tracking probes are promising in deciphering the fate of hydrogels after transplantation. Herein, we reported a noninvasive in vivo hydrogel tracking method using UCNPs and found that the fluorescence intensity change from the UCNPs was well consistent with the weight change of the hydrogels, suggesting the accuracy of UCNPs in tracking hydrogel degradation. This study provides inspirations on developing advanced NIR light regulated probes with great clinical translation potentials.

Melting Away Pain: Decay of Thermal Nociceptor Transduction during Heat-Induced Irreversible Desensitization of Ion Channels.

Thermal transient receptor potential channels play a key role in thermal sensation. Although predictive models exist for temperature-dependent transduction through these channels and for the associated sensations of pain, the ability to predict irreversible desensitization has been lacking. We explored the role of irreversible ion channel desensitization in pain sensation and hypothesized that desensitization of ion channels would follow the kinetics similar to the denaturation of catalytic enzymes. We therefore proposed a three-state model to simulate the kinetic of temperature-sensitive ion channels from the closed state through opening and irreversible thermal desensitization. We tested the model against data obtained in vivo from a feline model. The theoretical model predicts all experimental data with reasonable accuracy, and represents an important step toward the ability for understanding of the molecular basis of nociceptor signaling providing the possibility to design local anesthesia regimens and to the prediction of postoperative pain.

Pentaethylenehexamine-Loaded Hierarchically Porous Silica for CO2 Adsorption.

Recently, amine-functionalized materials as a prospective chemical sorbent for post combustion CO2 capture have gained great interest. However, the amine grafting for the traditional MCM-41, SBA-15, pore-expanded MCM-41 or SBA-15 supports can cause the pore volume and specific surface area of sorbents to decrease, significantly affecting the CO2 adsorption-desorption dynamics. To overcome this issue, hierarchical porous silica with interparticle macropores and long-range ordering mesopores was prepared and impregnated with pentaethylenehexamine. The pore structure and amino functional group content of the modified silicas were analyzed by scanning electron microscope, transmission electron microscope, N2 adsorption, X-ray powder diffraction, and Fourier transform infrared spectra. Moreover, the effects of the pore structure as well as the amount of PEHA loading of the samples on the CO2 adsorption capacity were investigated in a fixed-bed adsorption system. The CO2 adsorption capacity reached 4.5 mmol CO2/(g of adsorbent) for HPS-PEHA-70 at 75 °C. Further, the adsorption capacity for HPS-PEHA-70 was steady after a total of 15 adsorption-desorption cycles.

[Clinical value of cupping spot effect].

The cupping spot is considered as one kind of skin change due to cupping treatment. With literature regarding cupping spot, the influencing factors and value of cupping spot in clinical diagnosis and treatment were analyzed, which could make a further exploration on the action mechanism of cupping treatment. The literature showed that the formation of cupping spot was related with cupping temperature, pressure, cup-retaining time, cupping area, individual difference and health condition, etc; cupping spot had the ability to assist diagnosis, prevent disease, cure disease and evaluate clinical efficacy. Previous studies on cupping spot have already made some progress, and played a positive significance on finding cupping rule and studying its mechanism. However, the research for this area is still in the primary stage, which needed deeper study to reveal scientific connotations of cupping spot.

Isomorphic coordination polymers of cobalt(II), zinc(II) with a flexible ligand of cis,cis,cis-1,2,3,4-cyclopentanetetracarboxylic acid and their molecular alloys: crystal structures, thermal decomposition mechanisms and magnetic properties.

Three new isomorphic coordination polymers of Co(2+), Zn(2+) ions with flexible multicarboxylic acid ligand of the cis,cis,cis-1,2,3,4-cyclopentanetetracarboxylic acid (H(4)L), [Co(4)L(2)(H(2)O)(8)]·3H(2)O (1), [Zn(4)L(2)(H(2)O)(8)]·3H(2)O (2) and [Co(0.8)Zn(3.2)L(2)(H(2)O)(8)]·3H(2)O (3), have been synthesized under hydrothermal conditions and by means of controlling the pH of the reaction mixtures (with an initial pH of 6.0 for 1, 4.0 for 2, and 5.0 for 3, respectively). In the crystal of 1, two crystallographically different Co(2+) ions (Co1 and Co2) form a negatively-charged coordination polymeric chain, which contains a centrosymmetric, linear, trinuclear Co(2+) cluster (Co(3)L(2)) subunit; another crystallographically independent Co(2+) ion (Co3) coordinated to six water molecules acts as a counter ions to link the neighboring coordination polymeric chains via intermolecular H-bond interactions. The Co(2+) ions in 1 were completely and partially replaced by Zn(2+) ions to give 2 and 3, respectively. Complex 3 shows a novel molecular alloy nature, due to the random distributions of the Co(2+) and Zn(2+) ions. Three isomorphic complexes exhibit distinct thermal decomposition mechanisms. The deprotonated cis,cis,cis-1,2,3,4-cyclopentanetetracarboxylic acid ligands decompose at 420-750 °C to give the residue CoO in 1, ZnO + C in 2 and CoO + ZnO in 3. Complex 1 shows a complicated magnetic behavior with co-existence of antiferromagnetic exchange interactions between neighboring Co(2+) ions as well as strong spin-orbital coupling interactions for each Co(2+) ion; complex 3 exhibits a magnetically isolated high-spin Co(2+) ion behavior with strong spin-orbital coupling interactions.

Solvothermal syntheses, structures, and physical properties of four new coordination compounds constructed from a bent dicarboxylate ligand.

Four new coordination compounds, namely {[Cd(3)(L)(2)(mu(3)-OH)(2)(H(2)O)] x H(2)O}(n) (1), {Ni(L)(bipy)}(n) (2), {Cu(3)(L)(2)(bipy)(mu(2)-OH)(2)(DMF)(2)}(n) (3), and {Co(2)L(2)(H(2)L)(H(2)O)}(n) (4), have been synthesized by the solvothermal reaction of 4,4'-(hexafluoroisopropylidene)bis(benzoic acid) (H(2)L) with different transition metal ions in the presence of co-ligand 4,4'-bipyridine (bipy). Compound 1 displays a three-dimensional (3D) framework containing infinite bands constructed of heptanuclear cadmium clusters. In compound 2, [Ni(2)C(2)O(4)] secondary building units (SBUs) are linked by L(2-) ligands into a 1D ribbon, which are further assembled into a two-dimensional (2D) non-interpenetrated structure with {4(4) x 6(2)} topology. Compound 3 possesses a 3D framework with a new topology of {4(3)}(2){4(6) x 6(14) x 8(8)} net, while the structure of 4 is a duplicate interpenetrated 3D framework with {4(12) x 6(3)} net. Temperature-dependent magnetic studies reveal that 3 exhibits ferromagnetic coupling between adjacent Cu(II) ions. The photoluminescent property of 1 has been studied in the solid state at room temperature.