Schiff Reaction Research Articles

Cobalt-Based Cathode Catalysts for Oxygen-Reduction Reaction in an Anion Exchange Membrane Fuel Cell.

A novel cobalt-chelating polyimine (Co-PIM) containing an additional amine group is prepared from the condensation polymerization of diethylene triamine (DETA) and terephthalalehyde (PTAl) by the Schiff reaction. A Co, N-co-doped carbon material (Co-N-C), obtained from two-stage calcination in different gas atmospheres is used as the cathode catalyst of an anion exchange membrane fuel cell (AEMFC). The Co-N-C catalyst demonstrates a CoNx-type single-atom structure seen under high-resolution transmission electron microscopy (HRTEM). The Co-N-C catalysts are characterized by FTIR, XRD, and Raman spectroscopy as well. Their morphologies are also illustrated by SEM and TEM micrographs, respectively. Surface area and pore size distribution are found by BET analysis. Co-N-C catalysts exhibit a remarkable oxygen reduction reaction (ORR) at 0.8 V in the KOH(aq). From the LSV (linear-sweeping voltammetry) curves, the onset potential relative to RHE is 1.19–1.37 V, the half wave potential is 0.73–0.78 V, the Tafel slopes are 76.9–93.6 mV dec−1, and the average number of exchange electrons is 3.81. The limiting reduction current of CoNC-1000A-900 is almost the same as that of commercial 20 wt% Pt-deposited carbon particles (Pt/C), and the max power density (Pmax) of the single cell using CoNC-1000A-900 as the cathode catalyst reaches 361 mW cm−2, which is higher than Pt/C (284 mW cm−2).

Calcined Co(II)-Chelated Polyazomethine as Cathode Catalyst of Anion Exchange Membrane Fuel Cells.

Polyazomethine (PAM) prepared from the polycondensation between p-phenylene diamine (PDA) and p-terephthalaldehyde (PTAl) via Schiff reaction can physically crosslink (complex) with Co ions. Co-complexed PAM (Co-PAM) in the form of gel is calcined to become a Co, N-co-doped carbonaceous matrix (Co-N-C), acting as cathode catalyst of an anion exchange membrane fuel cell (AEMFC). The obtained Co-N-C catalyst demonstrates a single-atom structure with active Co centers seen under the high-resolution transmission electron microscopy (HRTEM). The Co-N-C catalysts are also characterized by XRD, SEM, TEM, XPS, BET, and Raman spectroscopy. The Co-N-C catalysts demonstrate oxygen reduction reaction (ORR) activity in the KOH(aq) by expressing an onset potential of 1.19–1.37 V vs. RHE, a half wave potential of 0.70–0.92 V, a Tafel slope of 61–89 mV/dec., and number of exchange electrons of 2.48–3.79. Significant ORR peaks appear in the current–voltage (CV) polarization curves for the Co-N-C catalysts that experience two-stage calcination higher than 900 °C, followed by double acid leaching (CoNC-1000A-900A). The reduction current of CoNC-1000A-900A is comparable to that of commercial Pt-implanted carbon (Pt/C), and the max power density of the single cell using CoNC-1000A-900A as cathode catalyst reaches 275 mW cm−2.

Histological and Chemical Analysis of Heavy Metals in Kidney and Gills of Boops boops: Melanomacrophages Centers and Rodlet Cells as Environmental Biomarkers.

Industrialization has resulted in a massive increase in garbage output, which is frequently discharged or stored in waterways like rivers and seas. Due to their toxicity, durability, bioaccumulation, and biomagnification, heavy metals (such as mercury, cadmium, and lead) have been identified as strong biological poisons. Their presence in the aquatic environment has the potential to affect water quality parameters and aquatic life in general. Teleosts’ histopathology provides a sensitive indicator of pollutant-induced stress, because their organs have a central role in the transformation of different active chemical compounds in the aquatic environment. In particular, the gills, kidneys, and liver are placed at the center of toxicological studies. The purpose of this study is to examine the morphological changes caused by heavy metals in the kidney and gills of Boops boops, with a focus on melanomacrophages centers (MMCs) and rodlet cells (RCs) as environmental biomarkers, using histological and histochemical stainings (hematoxylin/eosin, Van Gieson trichrome, Periodic Acid Schiff reaction, and Alcian Blue/PAS 2.5), and immunoperoxidase methods. Our findings show an increase of MMCs and RCs linked to higher exposure to heavy metals, confirming the role of these aggregates and cells as reliable biomarkers of potential aquatic environmental changes reflected in fish fauna. The cytological study of RCs and MMCs could be important in gaining a better understanding of the complicated immune systems of teleosts.

IMMOBILIZATION OF LEVOTHYROXINE IN QUATERNIZED N,N-DIETYL N-METHYL CHITOSAN HYDROGEL AND CHEMICAL NATURE OF THE INTERACTION

Immobilization of a thyroid hormone substitute of L-thyroxine on chitosan-based smart hydrogel structure was performed to reduce the side effects of the required daily dose. The hydrogel was obtained by the Schiff reaction of chitosan with acetaldehyde and quaternization with methyl iodide then by ion exchange with NaCl salt. Finally, a hydrogel was obtained from the treatment of chitosan-based salt at -200C. The amount of levothyroxine immobilized by physical sorption on the hydrogel was determined by molecular electron spectroscopy on basis especially absorption peak at 227 nm. Results of IR- and UV-Vis spectroscopic analyses revealed that the interaction between levothyroxine and hydrogel occurs mainly due to hydrogen bonding and orientation forces of intermolecular interaction

Effect of preservative-free and preserved prostaglandin analogues on the histology of cornea of adult male guinea pigs following repeated exposure.

Glaucoma is a group of eye diseases that can cause vision loss. Prostaglandin analogues (PGAs) are known to be first-line treatment for patients with glaucoma. Latanoprost is a good, efficient and well-tolerated PGA that is currently available as latanoprost with benzalkonium chloride (BAC) (Xalatan) and preservative-free (PF) prostaglandin analogue latanoprost (Monopost). Lately, using PF anti-glaucoma agents has been considered an essential procedure for enhancing glaucoma care. This study aimed to analyse the histological changes within the corneal tissue with the use of currently available preserved prostaglandins-derived eye drops and PF prostaglandin analogue. In this study, 40 male guinea pigs were divided into four equal groups. Control group, Latanoprost with 0.02% BAC-treated group, Recovery group and PF latanoprost-treated group. After 2 months, the corneal tissues of guinea pigs were prepared for light and electron microscopic studies; morphometric and statistical studies were performed. Our results indicated that guinea pigs treated with latanoprost with BAC exhibited ocular surface changes: there was epithelial thinning with desquamation, the stroma showed irregularly arranged collagen fibres and small keratocytes. Morphometrically, there was a marked decrease in the thickness of epithelium and number of keratocytes. Negative periodic acid Schiff (PAS) reaction was observed in some parts of the epithelial basement membrane. The epithelium gave a strong positive immunoreactivity for Bcl-2-associated X protein (BAX). Guinea pigs left to recover exhibited improvement, while treatment of animals with PF latanoprost resulted in nearly normal corneal structure. In conclusion, PF prostaglandin anti-glaucoma medication seems to be better and have protective effect on cornea of male guinea pigs than prostaglandins with BAC preservative.

Synthesis and Characterization of new 3-(2-(6-oxo-1,3-thiazinan-3-yl)-R)-1,3-oxazepane-4,7-dione and N-Bromo Amines 1,3-oxazepane-4,7-dione Derivatives.

This study includes synthesis and characterization of new derivatives of 3-(2-(6-oxo-1,3-thiazinan-3-yl)-R)-1,3-oxazepane-4,7-dione and N-Bromo amines 1,3-oxazepane-4,7-dione derivatives. Schiff's bases reactions through one step process in inert solvents. Some employing Schiff's bases [1- 4]; in addition, synthesized by the reaction of different amines with (Salicylaldehyde) in absolute ethanol under reflux. Heterocyclic rings of 1,3-oxazepane-4,7-dione prepared by the reaction of succinic anhydride with Schiff's bases [1-4] and 3-(2-(6-oxo-1,3-thiazinan-3-yl)-R)-1,3-oxazepane-4,7-dione derivatives were prepared by the reaction of 3-mercaptopropanoic acid with 1,3-oxazepane-4,7-dione[A1-A4] in 1,4-dioxan. Synthesis of some N-bromo amine derivatives by the reaction of 1,3-oxazepane-4,7-dione[A1-A4] with 2,4,4,6-TBCD (2,4,4,6-tetrabromocyclohexa-2,5-dienone) in dry benzene; The prepared compounds were identified by melting point, FT-IR, UV-Vis and 1H- NMR spectroscopy.

Room Temperature Acid-Free Greener Synthesis of Imine Using Cobalt-Doped Manganese Tungstate.

Facile synthesis of an imine compound through a greener route is still a challenging task. Industrial processes rely on the age-old Schiff reaction for the synthesis of imine, which are reversible and nongreen from an environmental viewpoint. Herein, cobalt-doped manganese tungstate with two different morphologies is synthesized and demonstrated as a recyclable catalyst for imine synthesis from the condensation of an aldehyde and an amine with 73% yield of an imine in a nonaqueous and nonacidic environment at room temperature. The high catalytic activity is attributed to cobalt doping, high surface area, strong acidic site, and the polar nature of the catalyst. The stability and recyclability test shows that the catalytic activity remains the same after several cycles, which is crucial from the industrial point of view. The formation of imine is found to follow an alternative mechanism in an irreversible manner with a polar four-membered intermediate unlike the conventional method. The demonstrated process has several advantages including irreversibility, "greener", environmental friendly, and energy-efficient.

Histological and Immunohistochemical Characterization of Vascular Alterations in Meninges of Cats Infected with Gurltia paralysans.

Gurltia paralysans, a metastrongyloid nematode, parasitizes in meningeal vessels in the thoracolumbar spinal cord of cats in South America and causes progressive paraparesis. Recently, the first report outside of South America described gurltiosis in a cat in Spain. As this parasitic disease has so far been largely neglected, especially outside of South America, the aim of the present case study was to add knowledge to the histologic and immunohistochemical characterization of central nervous lesions. To this purpose, formalin-fixed and paraffin-embedded (FFPE) tissue samples from the spinal cord and brain of five cats affected by clinical signs caused by Gurltia paralysans and of three control cats without CNS lesions were histopathologically examined using hematoxylin and eosin stain (HE), Elastica van Gieson stain, as well as periodic acid–Schiff (PAS) reaction. Moreover, immuno- histochemistry for alpha smooth muscle actin and Factor VIII-related antigen were performed to characterize vascular lesions. Lesions were consistent with previous descriptions and were mainly located in the spinal cord and consisted of chronic suppurative or lymphoplasmahistiocytic meningi tis as well as suppurative vasculitis, congestion and varicosis of meningeal veins. In view of the recent detection of this parasite in Europe and the increasing inner-European transport of rescued domestic cats, veterinarians in Europe should be aware of the clinical and pathomorphological presentation of this disease.

Protective effect of resveratrol on acrylamide-induced renal impairment.

Acrylamide (ACR) has a wide range of uses. It possesses a renal impairment effect. The work aimed to study the possible protecting role of resveratrol (RVS) over the ACR-mediated renal impairment in rats. The suggested underlying mechanisms participating in such protection were investigated. Thirty Sprague-Dawley adult albino rats were divided into three groups: control, ACR, and RVS. After 4 weeks, the kidney was removed and prepared for histological, immunohistochemical, and biochemical studies. The activity of tissue oxidative (malondialdehyde [MDA]) and anti-oxidative (glutathione [GSH]) markers were assessed. Acrylamide induced glomerular renal affection in the form of shrinkage and distortion of the glomeruli with wrinkling of their basement membranes and widening of the urinary spaces. Degenerative tubular changes were markedly present in the proximal convoluted tubules. The necrotic tubular cells exhibited cytoplasmic vacuolation with desquamated epithelial cells within the tubular lumen. ACR increases the deposition of collagen fibres in the basement membrane of the glomerular capillaries and induced thickening of the basement membranes of the renal corpuscles and renal tubules. The administration of RVS affords high protection to the kidney. The glomeruli and renal tubules were nearly normal. The content of collagen fibres and the periodic acid Schiff reaction of the basement membrane of the renal tubules were 70% and 19% lower linked to the ACR group. The creatinine and urea levels decreased by 51% and 47%. RVS induced such a protective role through its antioxidant effect as the MDA level decreased by 45%, while the GSH level increased by 83% compared with the ACR group. Acrylamide causes structural and functional disorders of the kidney. It induces kidney damage through oxidative stress and apoptosis. With the use of RVS, normal kidney architecture was preserved with little structural changes. Adding, functional kidney test became normal. RVS exerts its protective effect through its anti-apoptotic and antioxidant features.

Fe, N-Doped Metal Organic Framework Prepared by the Calcination of Iron Chelated Polyimines as the Cathode-Catalyst of Proton Exchange Membrane Fuel Cells.

Aromatic polyimine (PIM) was prepared through condensation polymerization between p-phenylene diamine and terephthalaldehyde via Schiff reactions. PIM can be physically crosslinked with ferrous ions into gel. The gel-composites, calcined at two consecutive stages, with temperatures ranging from 600 to 1000 °C, became Fe- and N-doped carbonaceous organic frameworks (FeNC), which demonstrated both graphene- and carbon nanotube-like morphologies and behaved as an electron-conducting medium. After the two-stage calcination, one at 1000 °C in N2 and the other at 900 °C in a mixture of N2 and NH3, an FeNC composite (FeNC-1000A900) was obtained, which demonstrated a significant O2 reduction peak in its current–voltage curve in the O2 atmosphere, and thus, qualified as a catalyst for the oxygen reduction reaction. It also produced a higher reduction current than that of commercial Pt/C in a linear scanning voltage test, and the calculated e-transferred number reached 3.85. The max. power density reached 400 mW·cm−2 for the single cell using FeNC-1000A900 as the cathode catalyst, which was superior to other FeNC catalysts that were calcined at lower temperatures. The FeNC demonstrated only 10% loss of the reduction current at 1600 rpm after 1000 redox cycles, as compared to be 25% loss for the commercial Pt/C catalyst in the durability test.

The ameliorative effect of curcumin on cryptorchid and non-cryptorchid testes in induced unilateral cryptorchidism in albino rat: histological evaluation.

Cryptorchidism, one or both hidden testes, is the most common abnormality of male sexual development. Subfertility or infertility is associated with both unilateral and bilateral cryptorchidism. In this study, we investigate the possible ameliorative effect of curcumin (Cur) on the induced-unilateral cryptorchidism testicular injury in both cryptorchid (Cryp) and non-cryptorchid (non-Cryp) scrotal testes through histological, immunohistochemical and morphometrics. Forty adult male albino rats were divided into: control group, Cur control group, Cryp group, and Cryp+Cur group. The rat model was surgically established by fixing the left testis in the abdomen. The treated groups were subjected to surgically induced-unilateral cryptorchidism on the left side then were given Cur (80 mg/kg) orally, for 20 days. Histological analysis using haematoxylin and eosin and periodic acid Schiff's reaction was done. Immunohistochemistry was performed for proliferating cell nuclear antigen (PCNA); to estimate the proliferation in the germinal epithelium, and vimentin; to evaluate Sertoli cells. The results were confirmed by statistical evaluation of the spermatogenic epithelium height, the seminiferous tubules diameter, the basement membrane thickness, the number of PCNA immunostained cells and the area per cent of vimentin immunostaining. Distorted seminiferous tubules, substantial degeneration of the germinal epithelium, thickening of the basement membrane with a significant decrease in PCNA and vimentin immunostaining were observed in Cryp group; mainly in the cryptorchid testis. These structural changes were significantly reversed in Crypt+Cur group. Curcumin proved to be an important and effective medical line for protecting against the unfavourable sequels of cryptorchidism in a rat model.

Anionic covalent organic framework as an interlayer to fabricate negatively charged polyamide composite nanofiltration membrane featuring ions sieving

Ions sieving is significant but challengeable for seawater desalination, industrial water treatment and salts recovery. Traditional nanofiltration (NF) membranes suffer from undesirable ion selectivity and permeance due to uncontrolled aromatic polyamide (PA) nanofilm. Herein, we first reported an anionic covalent organic framework (TpPa-SO3Na) with abundant sulfonic acid groups as a mediating interlayer to fabricate PA composite membrane. The uniform and negatively charged TpPa-SO3Na spherical nanoparticles were in situ soldering on nylon substrate by liquid–liquid interfacial Schiff reaction. The TpPa-SO3Na interlayer assisted in creating a defect-free PA nanofilm through mediating the diffusion–reaction process of amine monomers. According to enhanced Donnan effect, the composite polyamide nanofiltration membrane showed an outstanding salt rejection ratio (Na2SO4, 99.6%), high single salt selectivity (NaCl/Na2SO4, 178.5) and mono/divalent anion selectivity (Cl−/SO42−, 312.6), superior to most reported NF membranes. This work shed light on strategies to synthesize emerging covalent organic framework materials and to effectively construct NF composite membranes with excellent solute retention and ions sieving capabilities.

Crop Morpho-Histological Peculiarities in Domesticated Pigeons (Columba livia domestica), Cattle Egret (Bubulcus ibis) and Domesticated Ducks (Anas platyrhynchos domestica)

The crop architecture varies among different avian species consistent with their feeding habits. Therefore, twenty-one of mature healthy male pigeons (granivorous), cattle egrets (carnivorous), and ducks (omnivorous), seven per species, were utilized for the histological, immunohistochemical, and ultrastructural analyses. Histologically, the mucosal folds were covered by non-keratinized stratified squamous epithelium in the three investigated species. The mucosal glands are only peculiar to the crops of the cattle egrets as well as the ducks, while the pigeons' crops were devoid of any secretory units. Morphometrically, the optical densities of the Alcian blue (AB) and periodic acid Schiff (PAS) reactions in the secretory glands, the area % of collagen fibers, the thickness of the tunica musculosa were measured and declared significant differences among the three studied avian species. Immunohistochemical reaction revealed ki-67 immuno-positive reactivity in the nuclei of basal cell layers of the crop epithelium in pigeons only. Regarding ultrastructure investigation, the covering epithelium of all studied species had been shown to be the basal layer of cuboidal to tall columnar cells with desmosomal junctions at the level of their cellular interdigitation, intermediate layers of large irregular polygonal cells with obviously increased cytokeratin filaments especially in the ducks and cellular interdigitation in between. The superficial layer of flat-shaped cells in the three investigated species manifested by desmosomal junctions in between but at the level of the surface squamous cells of the superficial layer, a fine lateral process is only inspected in the pigeons. In conclusion, the crop glands characterized by supranuclear electron dense secretory granules in the cattle egrets and electron-lucent in ducks.

SYNTHESIS, CHARACTERIZATION AND ANTI-MICROBIAL EVALUATION OF A SERIES OF QUINAZOLINE ANALOGS

A series of substituted 6-bromo-3-(3-chloro-2-oxo-4-arylazetidin-1-yl)-2-methylquinazolin-4(3H)-one has been synthesized and evaluated for their biological activity. The title compounds (G1-G10) were prepared by the reaction of 5- bromo anthranilic acid with acetic anhydride to form 6-bromo-2-methyl-4H-benzo[1,3]oxazin-4-one which upon treatment with hydrazine hydrate in the presence of anhydrous pyridine form 3-amino-6-bromo-2-methylquinazolin- 4(3H)-one. The resulting intermediate underwent Schiff reaction with different aromatic aldehyde followed by reflux with chloroacetyl chloride and triethylamine. Ten different quinazoline derivatives (G1-G10) were synthesized. Structural assignments of these compounds have been made by elemental analysis, FTIR, 1HNMR 8 Mass spectral data and the purity of the compounds was determined by TLC. The anti-microbial activity of the newly isolated heterocyclic compounds was evaluated against Gram-positive, Gram-negative bacteria and fungi. Most of the compounds showed a moderate degree of anti-microbial activity. The study concluded that the compound G4 8 G6 were found to exhibit significant anti-bacterial activity when compared to Amoxicillin as standard drug while compound G7 exhibit significant anti-fungal activity when compared to Fluconazole as standard drug.

THE ORAL SUCKER OF SOME GASTROINTESTINAL TREMATODES: HISTOLOGICAL AND HISTOCHEMICAL RESEARCH

We conducted histological and histochemical studies of the oral sucker of gastrointestinal trematodes of the family Paramphistomatidae, Fischoeder, 1901 living in the rumen of ruminants, namely, Liorchis scotiae, Paramphistomum cervi and Paramphistomum ichikawai. The oral sucker of paramphistomes and the Liorchis scotiae trematode is a complex muscular organ modified into a pharynx-sucker, the muscle complex of which is formed from longitudinal, circular and radial muscle fibers. In the thick pharynx wall, we found secretory cells, single neurosecretory cells and many desmoblastic cells of connective tissue. Histochemical stains showed intense staining with alcian blue, toluidine blue, bromophenol blue and a positive periodic acid Schiff reaction, which indicates the presence of glycosaminoglycans, total proteins and glycoproteins. Due to this structure, the pharynx sucker of gastrointestinal trematodes is involved in capturing food and evacuating its undigested residues from the helminth's body to the outside. In addition, the substances produced by secretory cells of the pharynx carry out a partial chemical treatment of the food consumed by the parasite and protect the parasite from substances that are metabolites of the host tissues and waste products of symbionts and commensals that inhabit the rumen of ruminants. Thus, trophic adaptation of the parasite in its ecological niche, the rumen of polygastric mammals, is ensured.

Cellulose Nanocrystals as Template for Improving the Crystallinity of Two-Dimensional Covalent Organic Framework Films.

Despite the rapid development of two-dimensional covalent organic frameworks (2D COFs) in recent years, it remains a great challenge to synthesize highly crystalline COF materials. Here, a CNC-assisted approach was adopted to synthesize high crystallinity COF materials. A series of 2D COF films were synthesized at the air–water interface by using cellulose nanocrystals (CNCs) as the template. The occurrence of Schiff reactions based on the imine bond was demonstrated by Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) exhibited the appearances of 2D COF films were flower-like. When CNCs were added to a certain extent, the size of a single petal in the flowers gradually increased with the amount of CNCs. The film with large petals was characterized by Ultraviolet–Visible diffuse reflectance spectroscopy (UV–Vis DRS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). In UV–Vis DRS curves, the S-band of COF-366 film was red-shifted by 24 nm compared with that of 5,10,15,20-tetrakis(4-aminophenyl)-21H,23H-porphyrin (TAPP), confirming the existence of extended conjugation in COF-366 film. XPS was used to identify the surface composition of the sample. The N1s signal of the film indicated that each TAPP formed four imine bonds with 2,5-dihydroxyterephthalaldehyde (DHTA) in COF-366 film. TEM images showed that CNCs had an influence on the crystal size. It was observed from SAED that the crystallinity of the film with CNCs was higher than the film without CNCs. This work provided a new template for improving the crystallinity of 2D COF films.

A Facile Method for the Preparation of Hydrophilic-Hydrophobic Functional Thermo-pH Responsive Terpolymers Based on Poly (NIPAAm-co-DMAA-co-DMAMVA) and Post-polymerization

A new monomer has been synthesized on the basis of vanillin. This compound has the advantage of having a tertiary amine group, which makes it one of the pH-responsive monomers. Moreover, the active aldehyde group facilitates the additional reaction modification like the post-polymerization through Schiff reaction by reaction with primary amine compounds like amino acids. The name of the compound is 2-((dimethylamino)methyl)-4-formyl-6-methoxyphenyl acrylate (DMAMVA). The compounds have been evaluated by 1H, 13C NMR, and FTIR. A new series of polymers has been fabricated by free radical polymerization of N,N-dimethylacrylamide, and 5, 10, and 15 mol% of DMAMVA with N-isopropylacrylamide to produce the dual-responsive thermo-pH polymers. They were reacted with amino acid by post-polymerization according to Schiff base click reaction. All polymers have been investigated chemically in addition to physical characterizations e.g., molecular weight by GPC, glass transition temperature by DSC, chemical decomposition TGA, and morphological by SEM. The study was focused on the determination of phase transition temperatures and LCST of the polymer solution; it has been done using two methods one by UV–VIS-spectroscopy as turbidity test, while the other new technology by micro-DSC. More applications for these polymers will be applied in bio-separation and biotechnology in our future work.

Multifunctional Organic Fluorescent Probe with Aggregation-Induced Emission Characteristics: Ultrafast Tumor Monitoring, Two-Photon Imaging, and Image-Guide Photodynamic Therapy.

The development of multifunctional photosensitizers (PSs) with aggregation-induced emission (AIE) properties plays a critical role in promoting the progress of the photodynamic therapy (PDT). In this work, a multifunctional PS (named DSABBT NPs) with AIE activity has been designed and prepared to carry out ultrafast staining, excellent two-photon bioimaging, and high-efficiency image-guided PDT. Simply, DSABBT with AIE characteristic was synthesized by one-step Schiff reaction of 4-(diethylamino)-salicylaldehyde (DSA) and 4,7-bis(4-aminophenyl)-2,1,3-benzothiadiazole (BBT). Then, DSABBT and DSPE-PEG2000-cRGD generate nanoparticles (NPs) easily in an ultrapure water/tetrahydrofuran mixture through a facile nanoprecipitation at room temperature. We found that DSABBT NPs exhibit bright solid-state fluorescence with large stokes shifts (180 nm) and two-photon absorption cross-section (1700 GM). Importantly, DSABBT NPs exhibited excellent ability of ultrafast staining and two-photon imaging, which can readily label suborganelles by subtly shaking the living cells for 5 s under mild conditions. Moreover, DSABBT NPs displayed high singlet oxygen (1O2) generation capacity and remarkable image-guided PDT efficiency. Therefore, DSABBT NPs can act as the promising candidate for multifunctional PSs, which can destroy cancer cells and block malignant tumor growth via the production of reactive oxygen species upon irradiation conditions. These outcomes provide us with a selectable strategy for developing multifunctional theranostic systems.

Difunctional covalent organic framework hybrid material for synergistic adsorption and selective removal of fluoroquinolone antibiotics

Due to the low efficiency of traditional sewage treatment methods, the effective removal of zwitterionic fluoroquinolone (FQs) antibiotics is of vital significant for environment protection. In this work, a SO3H-anchored covalent organic framework (TpPa-SO3H) was deliberately designed by linking phenolic trialdehyde with triamine through Schiff reaction, then low-content Tb3+ ions were loaded onto covalent organic framework according to wet-chemistry immersion dispersion method which benefitting for efficient FQs antibiotics uptaking. Tb@TpPa-SO3H functionalized with regularly distributed sulfonic acid groups and terbium ions which could provide difunctional binding sites. Tb3+ sites could capture carboxylic acid group of FQs molecules according to the complexes coordination effect and sulfonic acid sites play a significant role in the adsorption of FQs molecules through electrostatic interaction with amine group. Tb@TpPa-SO3H with dual complementary function sites exhibited ultra-fast adsorption kinetics (< 2min, average over 99% removing rate) and high adsorption capacities of 989, 956, and 998mgg-1 for Norfloxacin (NOR), ciprofloxacin (CIP), enrofloxacin (ENR), respectively. Furthermore, Tb@TpPa-SO3H showed excellent selectivity for the adsorption of FQs in tanglesome system. This work not only explored synergistic adsorption in ion-functionalized 2D covalent organic framework with dual binding sites, but also delineated a promising strategy for the elimination of organic pollutants in environmental remediation.

Algorithm for morphological diagnosis of neoplasms in the chiasmal-sellar region

In the Turkish saddle area, there is a wide variety of pathological processes, the vast majority of which present as tumors of various origins (up to 90%). For a clear morphological verification of the diagnosis, it is proposed to use a diagnostic algorithm that includes the stages of differential diagnosis of normal adenohypophysis and neurohypophysis with tumors in the anterior and posterior lobes of the pituitary gland, non-pituitary origin neoplasms, as well as with non-tumor pathological processes (inflammation, cystic masses, and hyperplasia). For morphological diagnosis, histochemical and immunohistochemical methods are recommended using various staining techniques (silver impregnation, periodic acid Schiff reaction) of tissue specimens and antibody panels (pituitary hormones, low-molecular cytokeratins, pituitary transcription factors, neuroendocrine markers, etc.).