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Carbon dots (C-Dots), with unique properties from tunable photoluminescence to biocompatibility, show wide applications in biotechnology, optoelectronic device and catalysis. Chiral C-Dots are expected to have strongly chirality-dependent biological and catalytic properties. For chiral C-Dots, a clear structure and quantitative structure-property relationship need to be clarified. Here, chiral C-Dots were fabricated by electrooxidation polymerization from serine enantiomers. The oxidized serine has a reversed chiral configuration to serine, which leads to the chiral C-Dots possessing inverse handedness compared with their raw materials. Electron circular dichroism spectrum, together with other diverse characterization techniques and theoretical calculations, confirmed that these chiral C-Dots (2-7 nm) have a well-defined primary structure of polycyclic dipeptide and possess a spatial structure with a

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer-related death worldwide. It involves the complex interactions between genetic factors, environmental exposure, and gut microbiota. Specific changes in the gut microbiome and metabolome have been described in CRC, supporting the critical role of gut microbiota dysbiosis and microbiota-related metabolites in the tumorigenesis process. Short-chain fatty acids (SCFAs), the principal metabolites generated from the gut microbial fermentation of insoluble dietary fiber, can directly activate G-protein-coupled receptors (GPCRs), inhibit histone deacetylases (HDACs), and serve as energy substrates to connect dietary patterns and gut microbiota, thereby improving the intestinal health. A significantly lower abundance of SCFAs and SCFA-producing bacteria has been demonstrated in CRC, and the supplementation of SCFA-producing probiotics can inhibit intestinal tumor development. SCFAs-guided modulation in both mouse and human CRC models augmented their responses to chemotherapy and immunotherapy. This review briefly summarizes the complex crosstalk between SCFAs and CRC, which might inspire new approaches for the diagnosis, treatment and prevention of CRC on the basis of gut microbiota-derived metabolites SCFAs.

We report a single-frequency linearly polarized Q-switched fiber laser based on a Nb2GeTe4 saturable absorber (SA). The Nb2GeTe4 SA triggers passive Q-switching of the laser, and an un-pumped Yb-doped fiber together with a 0.08-nm-bandwidth polarization-maintaining fiber Bragg grating act as an ultra-narrow bandwidth filter to realize single-longitudinal-mode (SLM) oscillation. The devices used in the laser are all polarization-maintaining to ensure linearly polarized laser output. Stable SLM linearly polarized Q-switching operation at 1064.6 nm is successfully achieved with a shortest pulse width of 1.36 μs, a linewidth of 28.4 MHz, a repetition rate of 28.3-95.9 kHz, and a polarization extinction ratio of about 30 dB. It is believed that the single-frequency linearly polarized pulsed fiber laser studied in this paper has great application value in gravitational wave detection, beam combining, nonlinear frequency conversion, and other fields.

There is an increasing need for rapid and on-site detection of emerging drugs of abuse. In this work, we developed a method using a miniature dual-LIT (linear ion trap) mass spectrometer recently developed with comprehensive tandem mass spectrometry analysis capability, for qualitative and quantitative analysis of multiple drugs of abuse. Paper-capillary spray cartridges were used with related workflow established to simplify overall analysis procedure. Quantitation of ketamine and methamphetamine was achieved by beam-type collision-induced dissociation on the miniature dual-LIT mass spectrometer and a linear concentration range of 100–5000 ng/mL was obtained. The system has been applied in analysis of real urine samples from individuals addicted to morphine and methamphetamine use. The changes of the ratio of cocaine to its metabolite benzoylecgonine were also explored to estimate the time of cocaine intaking.

High-fat diet (HFD) leads to long-term exposure to gut microbial metabolite secondary bile acids such as deoxycholic acid (DCA) in the intestine, which is closely linked to colorectal cancer (CRC). Evidence reveals that vasculogenic mimicry (VM) is a critical event for the malignant transformation of cancer. Therefore, we aimed to investigate the crucial roles of DCA on the regulation of VM and the progression of intestinal carcinogenesis. The effects of HFD on VM formation and epithelial-mesenchymal transition (EMT) in human CRC tissues were investigated. The fecal DCA level was detected in the HFD treated-Apcmin/+ mice. Then the effects of DCA on VM formation, EMT and vascular endothelial growth factor receptor 2 (VEGFR2) signaling were evaluated in vitro and in vivo. Here we demonstrated that compared with the normal diet, HFD exacerbated VM formation and EMT in CRC patients. HFD could alter the composition of the gut microbiota and significantly increase fecal DCA level in Apcmin/+ mice. More importantly, DCA promoted tumor cell proliferation and EMT, and increased VM formation accompanied by VEGFR2 activation, which led to intestinal carcinogenesis. In addition, DCA enhanced the proliferation and migration of HCT-116 cells, and induced EMT process and vitro tube formation. Furthermore, the silence of VEGFR2 blunted DCA-induced EMT, VM formation and migration. Collectively, our results indicated that microbial metabolite DCA promoted VM formation and EMT through VEGFR2 activation, which further exacerbated intestinal carcinogenesis.

Accumulating evidence from studies in humans and animal models has elucidated that gut microbiota, acting as a complex ecosystem, contributes critically to colorectal cancer (CRC). The potential mechanisms often reported emphasize the vital role of carcinogenic activities of specific pathogens, but in fact, a series of metabolites produced from exogenous dietary substrates or endogenous host compounds occupy a decisive position similarly. Detrimental gut microbiota-derived metabolites such as trimethylamine-N-oxide, secondary bile acids, hydrogen sulfide and N-nitroso compounds could reconstruct the ecological composition and metabolic activity of intestinal microorganisms and formulate a microenvironment that opens susceptibility to carcinogenic stimuli. They are implicated in the occurrence, progression and metastasis of CRC through different mechanisms, including inducing inflammation and DNA damage, activating tumorigenic signaling pathways and regulating tumor immunity. In this review, we mainly summarized the intimate relationship between detrimental gut microbiota-derived metabolites and CRC, and updated the current knowledge about detrimental metabolites in CRC pathogenesis. Then, multiple interventions targeting these metabolites for CRC management were critically reviewed, including diet modulation, probiotics/prebiotics, fecal microbiota transplantation, as well as more precise measures such as engineered bacteria, phage therapy and chemopreventive drugs. A better understanding of the interplay between detrimental microbial metabolites and CRC would hold great promise against CRC.

A novel polyhedral oligomeric siloxane (POSS)-based zwitterionic monolithic capillary column was prepared via one-pot polymerization in ionic liquid porogen, using N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl)ammonium betaine (DMMSA) and methacrylic ethyl trimethylammonium chloride (META) as binary functional monomers, and methacryl substituted POSS as cross-linker. The pore structure, permeability and homogeneity were well tuned by optimizing the polymerization conditions. The resultant monolith was characterized by scanning electron microscopy, nitrogen adsorption/desorption isotherm and Fourier transform infrared spectroscopy. The incorporation of zwitterionic ligand (DMMSA), quaternary amine group (META) and rigid POSS skeleton endows the hybrid organic-silica monolith with high hydrophilicity, electrostatic interaction and good mechanical stability, as well as a tunable electroosmotic flow over wide pH range. A close investigation of capillary electrochromatographic separations of different types of polar compounds such as bases, nucleosides and benzoic acids on such stationary phase exhibited a retention independent column efficiency up to 118,000 plates/m (thiourea), as well as a mixed-mode hydrophilic interaction chromatography (HILIC) retention mechanism including weak electrostatic interaction, hydrophobic interaction and anion exchange.

The master oscillator power amplifier structure has been widely employed to realize high-power and narrow-linewidth output in fiber lasers. However, the stimulated Raman scattering (SRS) effect would appear in high-power operation and even become an important limitation on further power scaling, especially when the seed lasers are based on a fiber Bragg grating (FBG) pair. In order to improve SRS suppressing ability, a composite cavity structure was demonstrated by employing an additional wide-bandwidth low-reflectivity FBG outside the conventional oscillator. After passing through a piece of 50 m SMF-28e fiber, thanks to the improved temporal stability of the composite oscillator, the proportion of Raman Stokes light dropped dramatically compared with the proportion in a conventional fiber oscillator. This composite cavity design could provide a simple and compact approach for SRS suppression in a high-power narrow-linewidth fiber laser system.

As a class of the commonly used drugs in clinical practice, non-steroidal anti-inflammatory drugs (NSAIDs) can cause a series of adverse events including gastrointestinal injuries. Besides upper gastrointestinal injuries, NSAID enteropathy also attracts attention with the introduction of capsule endoscopy and double balloon enteroscopy. However, the pathogenesis of NSAID enteropathy remains to be entirely clarified. Growing evidence from basic and clinical studies presents that gut microbiota is a critical factor in NSAID enteropathy progress. We have reviewed the recent data about the interplay between gut microbiota dysbiosis and NSAID enteropathy. The chronic medication of NSAIDs could change the composition of the intestinal bacteria and aggravate bile acids cytotoxicity. Meanwhile, NSAIDs impair the intestinal barrier by inhibiting cyclooxygenase and destroying mitochondria. Subsequently, intestinal bacteria translocate into the mucosa, and then lipopolysaccharide released from gut microbiota combines to Toll-like receptor 4 and induce excessive production of nitric oxide and pro-inflammatory cytokines. Intestinal injuries present in the condition of intestinal inflammation and oxidative stress. In this paper, we also have reviewed the possible strategies of regulating gut microbiota for the management of NSAID enteropathy, including antibiotics, probiotics, prebiotics, mucosal protective agents, and fecal microbiota transplant, and we emphasized the adverse effects of proton pump inhibitors on NSAID enteropathy. Therefore, this review will provide new insights into a better understanding of gut microbiota in NSAID enteropathy.

Limited research has been conducted on the heavy metal (loid) (HM) exchanges among seawater, sediments and cultured mussels in mariculture areas. To determine the impacts of mussel mariculture on the transfer and risks of HMs in coastal environments, samples of seawater, sediments and cultured mussels from a typical mariculture area in the South China Sea were analysed. The logarithmic partition coefficients of sediment/water indicated that HMs were preferentially retained by sediments. There were relatively low ecological risks in mussel raft mariculture areas. Principal component analysis and correlation analysis revealed the influences of terrestrial input and ocean circulation on the HMs in seawater, and the bioaccumulation factors reflected the possible accumulation of HMs in seawater by cultured mussels. Mussel farming was the indirect source of HMs in sediments, and the biochemical processes of cultured mussels promoted the transfer and accumulation of HMs into sediments. Health risk assessment revealed that children were more susceptible than adults, and Cd, As and Cr were among the threatening elements. Nonetheless, the health risks that were possibly caused by the daily consumption of farmed mussels were still within safe limits. Thus, the potential pollution remediation and biomonitoring functions of mussel aquaculture in coastal water environments will be further studied in the future.

Background: High-fat diet (HFD) leads to exposure to gut microbial metabolite secondary bile acids such as deoxycholic acid (DCA) in the intestine, which is closely linked to colorectal cancer (CRC). Vasculogenic mimicry (VM) is a critical event for cancer malignant transformation. We aimed to investigate the crucial roles of DCA on VM and the intestinal carcinogenesis. Methods: The effects of HFD on VM formation and epithelial-mesenchymal transition (EMT) in human CRC tissues were investigated. The fecal DCA level was detected in the HFD treated- Apc min/+ mice. The four-week Apc min/+ mice were treated with 0·2% DCA for 12 weeks. Intestinal tumor tissues were collected for detection of VM, EMT, and vascular endothelial growth factor receptor 2 (VEGFR2) signaling. The effects of DCA on tube formation, EMT, and VEGFR2 signaling of HCT-116 cells were evaluated. Findings: Compared with the normal diet, HFD exacerbated VM formation and EMT in CRC patients. HFD could significantly increase fecal DCA level in Apc min/+ mice. More importantly, DCA promoted tumor cell proliferation and EMT, and increased VM formation accompanied by VEGFR2 activation, which led to intestinal carcinogenesis. DCA enhanced proliferation and migration of HCT-116 cells, and induced EMT and vitro tube formation. Furthermore, the silence of VEGFR2 blunted DCA-induced EMT, VM formation, and migration. Interpretation: Microbial metabolite DCA promoted VM formation and EMT through VEGFR2 activation, which further exacerbated intestinal carcinogenesis. Funding: This study was supported by the National Natural Science Foundation of China and the Key Project of Science and Technology Pillar Program of Tianjin. Declaration of Interest: The authors declare no conflicts of interest. Ethical Approval: This study was approved by the Ethics Committee of General Hospital, Tianjin Medical University, China.

Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease throughout the world. The relationship between gut microbiota and NAFLD has been extensively investigated. The gut microbiota is involved in the regulation of NAFLD by participating in the fermentation of indigestible food, interacting with the intestinal mucosal immune system, and influencing the intestinal barrier function, leading to signaling alteration. Meanwhile, the microbial metabolites not only affect the signal transduction pathway in the gut but also reach the liver far away from gut. In this review, we focus on the effects of certain key microbial metabolites such as short-chain fatty acids, trimethylamine-N-oxide, bile acids, and endogenous ethanol and indole in NAFLD, and also summarize several potential therapies targeting the gut-liver axis and modulation of gut microbiota metabolites including antibiotics, prebiotics, probiotics, bile acid regulation, and fecal microbiota transplantation. Understanding the complex interactions between microbial metabolites and NAFLD may provide crucial insight into the pathogenesis and treatment of NAFLD.

In this paper, we establish some new Foxby equivalences between some Gorenstein subcategories in the Auslander class 𝒜C(R) and that in the Bass class ℬC(S) in a general setting. Our results provide...

The human body harbors a vast array of microbiota that modulates host pathophysiological processes and modifies the risk of diseases including cancer. With the advent of metagenomic sequencing studies, the intratumoural microbiota has been found as a component of the tumor microenvironment, imperceptibly affecting the tumor progression and response to current antitumor treatments. The underlying carcinogenic mechanisms of intratumoural microbiota, mainly including inducing DNA damages, activating oncogenic signaling pathways and suppressing the immune response, differ significantly in varied organs and are not fully understood. Some native or genetically engineered microbial species can specifically accumulate and replicate within tumors to initiate antitumor immunity, which will be conducive to pursue precise cancer therapies. In this review, we summarized the community characteristics and therapeutic potential of intratumoural microbiota across diverse tumor types. It may provide new insights for a better understanding of tumor biology and hint at the significance of manipulating intratumoural microbiota.

Digital watermarking is a technique used to protect an author’s copyright and has become widespread due to the rapid development of multimedia technologies. In this paper, a novel watermarking algorithm using the nonsubsample shearlet transform is proposed, which combines the directional edge features of an image. A shearlet provides an optimal multiresolution and multidirectional representation of an image based on distributed discontinuities such as edges, which ensures that the embedded watermark does not blur the image. In the proposed algorithm, the nonsubsample shearlet transform is used to decompose the cover image into directional subbands, where different directional subbands represent different directional and textured features. The subband whose texture directionality is strongest is selected to carry the watermark and is thus suitable for the human visual system. Next, singular value decomposition is performed on the selected subband image. Finally, the watermark is embedded in the singular value matrix, which is beneficial for the watermarking robustness and invisibility. In comparison with related watermarking algorithms based on discrete wavelet transforms and nonsubsample contourlet transform domains, experimental results demonstrate that the proposed scheme is highly robust against scaling, cropping, and compression.

PI3K/AKT signaling is known to regulate cancer metabolism, but whether metabolic feedback regulates the PI3K/AKT pathway is unclear. Here, we demonstrate the important reciprocal crosstalk between the PI3K/AKT signal and pentose phosphate pathway (PPP) branching metabolic pathways. PI3K/AKT activation stabilizes G6PD, the rate-limiting enzyme of the PPP, by inhibiting the newly identified E3 ligase TIRM21 and promotes the PPP. PPP metabolites, in turn, reinforce AKT activation and further promote cancer metabolic reprogramming by blocking the expression of the AKT inhibitor PHLDA3. Knockout of TRIM21 or PHLDA3 promotes crosstalk and cell proliferation. Importantly, PTEN null human cancer cells and in vivo murine models are sensitive to anti-PPP treatments, suggesting the importance of the PPP in maintaining AKT activation even in the presence of a constitutively activated PI3K pathway. Our study suggests that blockade of this reciprocal crosstalk mechanism may have a therapeutic benefit for cancers with PTEN loss or PI3K/AKT activation., The PI3K/AKT signalling pathway regulates cancer metabolism. Here, the authors show a reciprocal positive feedback crosstalk between the PI3K/AKT and pentose phosphate pathway which promotes tumourigenesis.

In order to establish the Foxby equivalences associated to strongly Gorenstein modules, we introduce the notions of strongly $\mathcal{W}_P$-Gorenstein, $\mathcal{W}_I$-Gorenstein and $\mathcal{W}_F$-Gorenstein modules and discuss some basic properties of these modules. We show that the subcategory of strongly Gorenstein projective left $R$-modules in the left Auslander class and the subcategory of strongly $\mathcal{W}_P$-Gorenstein left $S$-modules are equivalent under Foxby equivalence. The injective and flat case are also studied.

Treatment of the potassium salt of 1,3,5-benzenetricarboxylic acid with transition metal ions in aqueous solution produced a series of coordination complexes. Reaction of Ni(ClO4)2·6H2O with K3[C6H3(CO2)3] gave complexes 1, Ni3[C6H3(CO2)3]2(H2O)14·4H2O. The compound crystallized as trimers with two terminal Ni(H2O)5 units bridged by two benzenetricarboxylate ligands to a central Ni(H2O)4. Magnetic susceptibility data indicate the presence of either weak antiferromagnetic interactions between metal ions, or single ion anisotropy. Reaction of Co(ClO4)2·6H2O with K3[C6H3(CO2)3] gave complexes 2, Co3[C6H3(CO2)3]2(H2O)12. The complexes exists as a pendant chain coordination polymer with both bridging and terminal Co2+ ions. Each cobalt center is also coordinated to four water molecules. A systematic linear decrease in effective moment is observed below 100 K. This decrease can be understood entirely in term of crystal field and spin-orbit coupling effects on the individual Co(II) ions and implies magnetic interaction are weak. Magnetic susceptibility data were also obtained for the Co–BTCA complexes 3, Co(BTCA)(py)2·0.67py. These data can also be described as arising solely from single-ion effects due to the non-cubic environment around the Co2+ ion with no evidence of the presence of magnetic interactions. Reaction of Mn(ClO4)2·6H2O with K3[C6H3(CO2)3] gave complexes 4, Mn3(C6H3(CO2)3)2·8H2O. Magnetic susceptibility data indicate weak antiferromagnetic interactions and suggest that the complexes have a low dimensional structures.

Let [Formula: see text] be a ring with compatible endomorphisms [Formula: see text]. We investigate the quasi-Armendariz, Armendariz, McCoy, semicommutative properties and Property (A) of the ring [Formula: see text]. Our results yield more examples of quasi-Armendariz rings, Armendariz rings, McCoy rings, semicommutative rings and rings with Property (A).

Antibiotic resistance gene (ARG) residues and the mode of transmission in marine environments remain unclear. The sulfonamide (SAs) concentrations, different genes and total bacterial abundance in seawater and sediment of the Northern Yellow Sea were analyzed. Results showed the genes sul I and sul II were present at relatively high concentrations in all samples, whereas the gene sul III was detected fewer. The ARGs concentrations in the sediment were 10(3) times higher than those in water, which indicated sediment was essential ARG reservoir. Statistical analysis revealed the total antibiotic concentration was positively correlated with the relative abundance of the gene sul I and sul II. The relative abundances of the gene sul I and the gene sul II were also correlated positively with those of the gene int1. This correlation demonstrated that SAs exerted selective pressure on these ARGs, whereas the gene int1 could be implicated in the propagation of the genes sul I and sul II in marine environments.

The synthesis, structures and magnetic properties of linear chain complexes of metal ions with 4-cyanopyridine are reported (4-CNpy=4-cyanopyridine): [Cu(4-CNpy) 4 (H 2 O)](ClO 4 ) 2 and M(4-CNpy) 2 Cl 2 (MMn, Fe, Co, Ni, Cu). All compounds crystallize in monoclinic systems. Crystallographic data for [Cu(4-CNpy) 4 (H 2 O)](ClO 4 ) 2 ] n ( 1 ): space group P 2 1 / c with a = 13.225(3), b = 10.567(2), c = 20.522(3) A , β = 99.71(2)°, V = 2826.7(9) A 3 , Z = 4, D calc = 1.640 Mg m −3 , μ = 3.430 mm −1 . The compound contains primer CuL 4 units with the ligands bounded to copper ions through the ring nitrogens. These units are weakly linked into chains through semi-coordinated bonds between the nitrile nitrogen and an adjacent copper ion via the axial sites. The magnetic data show only a weak antiferromagnetic interaction ( θ CW = −0.52(1) K). Crystallographic data for [Cu(4-CNpy) 2 Cl 2 ] n ( 2 ): space group P 2 1 / n with a = 3.779(2), b = 25.711(12), c = 7.104(4) A , β = 95.98(4)°, V = 686.48(4) A 3 , Z = 2, D calc = 1.658 Mg m −3 , μ = 5.575 mm −1 . Crystallographic data for [Mn(4-CNpy) 2 Cl 2 ] n ( 6 ): space group P 2 1 / c with a = 3.700(2), b = 7.198(2), c = 26.520(5) A , β = 92.13(3)°, V = 705.8(4) A 3 , Z = 2, D calc = 1.572 Mg m −3 , μ = 1.303 mm −1 . Both dichloride compounds similar structures, consisting of chains of metal ions bibridged by chlorides with the 4-CNpy ligands coordinated to the metal ions in the axial sites through the pyridine nitrogens. The difference in space groups is caused by the different modes of packing the chains into 3D lattices. Infrared spectra and powder X-ray diffraction patterns indicate that the remaining compounds form an isostructural series. The powder magnetic susceptibilities have been measured between 2 and 300 K for all compounds. Antiferromagnetic exchange (Cu, Mn) or ferromagnetic exchange (Ni, Co, Fe) exists within the chains. The Ni, Co and Fe compounds order antiferromagnetically at 7.2(2), 2.1(2) and 4.6(2) K, respectively. Magnetic field induced transitions have been observed in these three compounds below their ordering temperatures. The copper and manganese data have been fit to models for Heisenberg antiferromagnetic linear chain with S = 1 2 and S = 5 2 with exchange constants J Co / k = −13.7(2) K and J Mn / k = −0.5 7(1) K, respectively. The nickel and cobalt data have been fit to models for ferromagnetic linear chains, with the nickel compound corresponding to a S = 1 Heisenberg model with exchange constant J / lk = +4.8(2) K, and the cobalt compound to a S = 1 2 ferromagnetic Ising linear chain with exchange constant J / k = + 6.6(2) K. The iron data has not been successfully to fit to any model. It is concluded that the total magnetic interaction between the chains has been increased by approximately 50% by the substitution of 4-CNpy for pyridine.

Nitrogen supply can improve crop growth and yield. An over-use of nitrogen fertilizer in greenhouse crop productions, however, causes many environmental problems. The aim of this study was to quantify the effects of nitrogen on fruit growth and yield so as to facilitate the optimization of nitrogen management for cucumber ( Cucumis sativus ) crop in greenhouses. Four experiments with different levels of nitrogen treatments, substrates and planting dates on cucumber (cv. Deltastar ) were conducted in greenhouses located at Shanghai during 2005 and 2007. Using data of one experiment, seasonal time courses of leaf nitrogen content ( N L ), leaf area per plant ( LA ), and the number of fruits growing per plant ( n FG ), as well as time course of the length of individual fruit growing on the plant ( L F ( i )) under different levels of nitrogen supply conditions were, respectively, determined as functions of a photo-thermal index ( PTI ). The impact of N L on LA was determined by curve fitting to the experimental data. The source/sink ratio ( LA / n FG ), an indicative of the source size per fruit, was then derived from the seasonal time courses of LA and n FG . The impact of N L on L F ( i ) was indirectly quantified by the relationship between source/sink ratio ( LA / n FG ) and the elongation rate of individual fruit ( R FL ( i )). Both the harvest date and fresh weight ( W F ( i )) of individual fruit growing at different node, and number of harvested fruits ( n FH ) were then calculated as functions of the fruit length. These quantitative relationships were assembled to form a model for predicting the effects of nitrogen on fruit growth and yield (fruit fresh weight per plant). Independent data from other experiments were used to validate the model. Our model gives satisfactory predictions of cucumber fruit growth and yield under different levels of nitrogen supply and growing season conditions. The coefficient of determination ( r 2 ) and the relative root mean squared error ( rRMSE ) between the predicted and measured values are, respectively, 0.92 and 0.22 ( r 2 , rRMSE ) for leaf area per plant, 0.90 and 0.24 for the number of fruits growing on the plant, 0.91 and 0.22, 0.90 and 0.23, and 0.92 and 0.21, respectively, for the length, harvest date and fresh weight of individual fruit growing on the plant, 0.94 and 0.20 for yield. The model may be used for the optimization of nitrogen management for cucumber production in greenhouses. Further model calibration and test would be needed when applying this model to a wider range of conditions.

An amorphous phase of Co3BTCA2(H2O)6 has been prepared (BTCA=1,3,5‐benzenetri‐ carboxylate). The static properties (dc susceptibility, hysteresis) of Co3BTCA2(H2O)6 are similar to those of other ‘‘glassy’’ magnetic systems, but the dynamics of Co3BTCA2(H2O)6 (absence of long relaxation times, disappearance of frequency dependence at low temperatures) are unusual. The amorphous phase is characterized by a narrow hysteresis loop at low temperature. For the hysteresis curve at 4.2 K, the coercive field is several hundred Oersted and the remnant magnetization is on the order of 10−2 Msat. The temperature dependence of the dc magnetic susceptibility shows an unusual field dependence below 30 K, with the largest effective moments being obtained in the smallest applied fields. The freezing temperature, Tf, in zero field, as determined by both dc and ac susceptibilities, has been found to be Tf=23 K. The ac susceptibility shows the characteristic spin glass frequency dependence, yet loses all frequency dependence...

The title compounds have been synthesized for the first time. The crystal structure of the copper compound has been determined to consist of chloride bibridged chains of copper ions with the 4‐cyanopyridine (4‐CNPy) ligands coordinated to the metal ions through the pyridine nitrogens in the axial sites. Chemical and powder x‐ray analysis indicate that the compounds form an isostructural series. The powder susceptibilities have been measured between 2 and 300 K. Effects of either antiferromagnetic exchange (Cu) or ferromagnetic exchange (Ni,Co) within the chains have been seen. The copper data has been fit to the model of a S=1/2 Heisenberg antiferromagnetic linear chain with exchange constant J/k=−13.7(2) K. The nickel data has been fit to the model of a S=1 ferromagnetic Heisenberg linear chain with exchange constant J/k=+4.8(2) K. The cobalt data has been fit to the model of a S=1/2 ferromagnetic Ising linear chain with exchange constant J/k=+6.6(2) K. The Ni and Co compounds order antiferromagnetically...