The d(10) route to dye-sensitized solar cells: step-wise assembly of zinc(II) photosensitizers on TiO2 surfaces

Dye-sensitized solar cells have been assembled using a sequential approach: a TiO2 surface was functionalized with an anchoring ligand, followed by metallation with Zn(OAc)(2) or ZnCl2, and subsequent capping with a chromophore functionalized 2,2`:6`,2 ``-terpyridine; the DSCs exhibit surprisingly good efficiencies confirming the effectiveness of the new strategy for zinc-based DSC fabrication

Light harvesting with Earth abundant d-block metals: development of sensitizers in dye-sensitized solar cells (DSCs)

Chemistry is facing the challenge of delivering new materials for energy harvesting and management. The development of a materials chemistry in which scarce elements are replaced by more abundant and sustainable materials is crucial to the commercial and societal acceptance of these new technologies. This review surveys the use of complexes of Earth abundant metals from the first row of the d-block as photosensitizers in dye-sensitized solar cells (DSCs), an emerging technology for solar light harvesting in which state-of-the-art devices currently use ruthenium or other platinum group metal complexes as photosensitizer

Cysteine Peptidase Cathepsin X as a Therapeutic Target for Simultaneous TLR3/4-mediated Microglia Activation

Microglia are resident macrophages in the central nervous system that are involved in immune responses driven by Toll-like receptors (TLRs). Microglia-mediated inflammation can lead to central nervous system disorders, and more than one TLR might be involved in these pathological processes. The cysteine peptidase cathepsin X has been recognized as a pathogenic factor for inflammation-induced neurodegeneration. Here, we hypothesized that simultaneous TLR3 and TLR4 activation induces synergized microglia responses and that these phenotype changes affect cathepsin X expression and activity. Murine microglia BV2 cells and primary murine microglia were exposed to the TLR3 ligand polyinosinic-polycytidylic acid (poly(I:C)) and the TLR4 ligand lipopolysaccharide (LPS), individually and simultaneously. TLR3 and TLR4 co-activation resulted in increased inflammatory responses compared to individual TLR activation, where poly(I:C) and LPS induced distinct patterns of proinflammatory factors together with different patterns of cathepsin X expression and activity. TLR co-activation decreased intracellular cathepsin X activity and increased cathepsin X localization at the plasma membrane with concomitant increased extracellular cathepsin X protein levels and activity. Inhibition of cathepsin X in BV2 cells by AMS36, cathepsin X inhibitor, significantly reduced the poly(I:C)- and LPS-induced production of proinflammatory cytokines as well as apoptosis. Additionally, inhibiting the TLR3 and TLR4 common signaling pathway, PI3K, with LY294002 reduced the inflammatory responses of the poly(I:C)- and LPS-activated microglia and recovered cathepsin X activity. We here provide evidence that microglial cathepsin X strengthens microglia activation and leads to subsequent inflammation-induced neurodegeneration. As such, cathepsin X represents a therapeutic target for treating neurodegenerative diseases related to excess inflammation

Comparative pathological findings in mute swans (Cygnus olor) naturally infected with highly pathogenic Avian influenza viruses H5N1 and H5N8 in Serbia

The aim of this study was to compare pathological lesions and viral antigen expression in the organs of mute swans (Cygnus olor) naturally infected with highly pathogenic avian influenza virus subtypes H5N1 and H5N8. The examination was conducted on the carcasses of 22 mute swans which died during the avian influenza outbreaks in Serbia in 2006 and 2016-2017. Avian influenza virus subtype H5N8 isolated from mute swans in 2016-2017 was clustered within the 2.3.4.4 Glade group B. After necropsy, lung, liver, spleen, pancreas, kidney and brain tissues were sampled for histopathology and immunohistochemical examination. Avian influenza virus nucleoprotein polyclonal antibodies were used for detecting the viral antigen in the examined tissues. The most significant gross lesions were necrosis and haemorrhages in the pancreas. Major histological lesions were multifocal necroses in the pancreas, spleen and liver, non-purulent encephalitis, lung congestion and oedema. Immunohistochemical demonstration of HPAIV nucleoprotein in pancreas and brain was strongly consistent with histological lesions in both infected groups. Our findings showed that pancreas was the most affected organ in all examined mute swans. In addition to increased mortality rate, similar pathological findings were detected in mute swans naturally infected with highly pathogenic avian influenza viruses H5N1 and H5N8

Sphaerospora molnari (myxozoa) kod šaranske mlađi

Sferosporidioza škrga je obolenje riba izazvano parazitom Sphaerospora molnari koji napada škrge i kožu. Prvo pojavljivanje sferosporidioze škrga kod šaranskih mladunaca utvrđeno je u Mađarskoj još 1972, zatim u Češkoj i Poljskoj, dok je kod nas obolenje prisutno od sredine osamdesetih godina prošlog veka. Molnar, koji je prvi је izučavao patogeni efekat ovog uzročnika, najpre ga je identifikovao kao Sphaerospora carassi. Češki istraživači Lom et Dycova detektovali su uzročnika sferosporidioze škrga iz škržnog materijala obolelih mladunaca šarana pomoću histološke sekcije tkiva i predložili da se parazitu da ime Sphaerospora molnari. Ovo obolenje je dosta često kod mladunaca ribnjačkog šarana i amura, pri čemu intenzitet infestacije može dostići čak i do 100%. Cilj ovog rada jeste da se utvrdi prisustvo obolenja izazvanog parazitom Sphaerospora molnari i da se isprate kliničke i patohistološke promene kod infestiranih mladunaca šarana. Istraživanja su sprovedena na 18 šaranskih ribnjaka u Srbiji, od 2008. do 2012. godine, a u sklopu sistemskog monitoringa najznačajnijih protozooza šarana. Mladunci šarana pregledani su tokom čitavog vegetacionog perioda. Praćene su kliničke promene, i uzimani su uzorci za nativnu mikroskopiju koja je rađena pomoću svetlosnog mikroskopa. Od inficiranih jedinki uzimano je tkivo škrga za patohistološku analizu koja je sprovedena klasičnom metodologijom, fiksiranjem u 10% formalinu, sečenjem 5 μm velikih isečaka koji su kalupljeni u parafin i bojenjem isečaka pomoću H&E. Prisustvo S. molnari ustanovljeno je kod mladunaca šarana od 20 dana do 3 meseca starosti. Na škrgama su bili prisutni razvojni stadijumi i zrele spore što se moglo uočiti na stratifikovanom epitelu škržnih filamenata. Spore su invadirale epitel i formirale velike klastere. Akumulacija razvojnih stadijuma i zrelih spora bila je prisutna je i kod dvostrukog sloja epitelnih ćelija koje pokrivaju sekundarne lamele, i to najčešće između unutrašnjeg i spoljašnjeg omotača izazivajući tako distenziju tkiva. Zaražene lamele podležu nekrozi, što dovodi do kretanja spora prema spolja. Veličina spora iznosila je 10 x 10 μm. Klinički, obolenje se manifestovalo pojavom beličastih depozita na škrgama kao posledica agregacije parazita na njima, pri čemu paraziti mogu da zauzmu i do 80% površine slojevitog epitela, prekrivajući pločice i lukove škrga. Pritisak parazita koji se razmnožavaju je takav da vrši ćelijsku deformaciju tkiva i na kraju se uočava istančanost citoplazme ćelija šktžnog epitela u obliku mreže. Pošto spore prekrivaju najveći deo respiratornog epitela, smanjuju otpornost organizma i stvaraju uslove za razvoj drugih uzročnika obolenja (prvenstveno trematoda), što Sphaerosporu molnari svrstava u patogene parazite. Lokalizacija, veličina spora odnosno razvojnih stadijuma S. molnari, kao i kliničke i patohistološke promene zabeležene tokom ovog istraživanja odgovaraju rezultatima koje su opisali ostali istraživači koji su se bavili ovom problematikom. Pošto ne postoji ni jedno adekvatno terapeutsko sredstvo, kontrola sferopsoridioze i dalje se bazira na pridržavanju osnovnih sanitarno–profilaktičkih mera, kao što su isušivanje objekata, izmrzavanje, mehanička obrada tla i dezinfekcija krečom

Understanding why replacing I3–/I– by cobalt(II)/(III) electrolytes in bis(diimine)copper(I)-based dye-sensitized solar cells improves performance

The performances of dye-sensitized solar cells (DSCs) comprising heteroleptic bis(diimine)copper( I ) based dyes combined with either [Co(bpy) 3 ] 2+/3+ , [Co(phen) 3 ] 2+/3+ or I 3 /I redox mediators (bpy 1/4 2,2 0 - bipyridine, phen 1/4 1,10-phenanthroline) have been evaluated. The copper( I ) dyes contain the anchoring ligand ((6,6 0 -dimethyl-[2,2 0 -bipyridine]-4,4 0 -diyl)bis(4,1-phenylene))bis(phosphonic acid), 1, and an ancillary ligand (2, 3 or 4) with a 2,9-dimethyl-1,10-phenanthroline metal-binding domain. Ligands 2 and 3 include imidazole 2 0 -functionalities with 4-(diphenylamino)phenyl (2) or 4-(bis(4-n-butoxy) phenylamino)phenyl (3) domains; in 4, the phen unit is substituted in the 4,7-positions with holetransporting 4-(diphenylamino)phenyl groups. The photoconversion efficiency, h, of each of [Cu(1)(2)] + , [Cu(1)(3)] + and [Cu(1)(4)] + considerably improves by replacing the I 3 /I electrolyte by [Co(bpy) 3 ] 2+/3+ or [Co(phen) 3 ] 2+/3+ , and after a change of electrolyte solvent (MeCN to 3-methoxypropionitrile). Due to the faster charge transfer kinetics and more positive redox potential, the cobalt-based electrolytes are superior to the I 3 /I electrolyte in terms of open-circuit voltage (V OC ), short-circuit current (J SC ) and h; values of V OC 1/4 594 mV, J SC 1/4 9.58 mA cm 2 and h 1/4 3.69% (relative to h 1/4 7.12% for N719) are achieved for the best performing DSC which contains [Cu(1)(4)] + and [Co(bpy) 3 ] 2+/3+ . Corresponding values for [Cu(1)(4)] + and I 3 /I DSCs are 570–580 mV, 5.98–6.37 mA cm 2 and 2.43–2.62%. Electrochemical impedance spectroscopy (EIS) has been used to study DSCs with [Cu(1)(4)] + and the three electrolytes. EIS shows that the DSC with I 3 /I has the highest recombination resistance, whereas the [Co(phen) 3 ] 2+/3+ electrolyte gives the highest chemical capacitance and V OC and, between [Co(bpy) 3 ] 2+/3+ and [Co(phen) 3 ] 2+/3+ , the higher recombination resistance. The [Co(phen) 3 ] 2+/3+ electrolyte exhibits the highest mass transport restrictions which result in a lower J SC and DSC efficiency compared to the [Co(bpy) 3 ] 2+/3+ electrolyte

Uticaj različitih muznih sistema na kvalitet mleka u toku muže krava

If the procedures of preparation for milking and finishing operations are conducted correctly, then it can be expected to produce top-quality milk. It is, therefore, necessary to know the basis of physiology of milk secretion, possible sources of contamination and handling procedures with milk after the milking. One of the essential conditions for reducing clinical and subclinical udder diseases and top-quality milk production (somatic cells count ≤ 400000/ml, the total number of microorganisms ≤100000/ml) is milking procedure that involves stimulating and hygienic procedures of udder preparation, milking process, after milking procedures and hygiene of milking equipment. The subject of this study was to determine the influence of preparatory procedures for milking, as well as the milking with different types of milking equipments on hygienic and bacteriological safety of raw milk on family farms.Ukoliko se postupci pripreme za mužu, muža i završne operacije, izvode pravilno, onda se može dobiti mleko vrhunskog kvaliteta. Zato je neophodno poznavanje osnova fiziologije lučenja mleka, mogućih izvora kontaminacije i postupaka sa mlekom posle muže. Jedan od bitnih uslova da se smanje kliničke i subkliničke bolesti vimena i proizvede mleko ekstra klase (broj somatskih ćelija ≤ 400000/ml, ukupan broj mikroorganizama ≤ 100000/ml) jeste procedura muže koja obuhvata stimulativne i higijenske procedure pripreme vimena, tok muže, proceduru nakon muže i higijenu aparata za mužu. Predmet istraživanja je bio da se utvrdi uticaj pripremnih postupaka muže, kao i sam proces muže različitim tipovima muznih uređaja na higijensku i bakteriološku ispravnost sirovog mleka na porodičnim farmama

Modular synthesis of simple cycloruthenated complexes with state-of-the-art performance in p-type DSCs

A modular approach based on Suzuki-Miyaura cross coupling and Miyaura borylation has been used to prepare two cyclometallated [Ru(N^N) 2 (C^N)] + complexes which possess either a carboxylic or phosphonic acid group attached via a phenylene spacer to the 4-position of the pyridine ring in the C^N ligand. The key intermediate in the synthetic pathway is [Ru(bpy) 2 ( 1 )] + where bpy = 2,2'-bipyridine and H 1 is 4-chloro-2-phenylpyridine. The crystal structure of [Ru(bpy) 2 ( 1 )][PF 6 ] is presented. Reaction of [Ru(bpy) 2 ( 1 )][PF 6 ] with 4-carboxyphenylboronic acid leads to [Ru(bpy) 2 (H 6 )][PF 6 ], while the phosphonic acid analogue is isolated as the zwitterion [Ru(bpy) 2 (H 5 )]. The cyclometallated complexes have been characterized by mass spectrometry, multinuclear NMR spectroscopy, absorption spectroscopy and electrochemistry. [Ru(bpy) 2 ( 5 )] adsorbs onto NiO FTO/NiO electrodes (confirmed by solid-state absorption spectroscopy) and its performance in p-type dye-sensitized solar cells (DSCs) has been compared to that of the standard dye P1; two-screen printed layers of NiO give better DSC performances than one layer. Duplicate DSCs containing [Ru(bpy) 2 (H 5 )] achieve short-circuit current densities ( J SC ) of 3.38 and 3.34 mA cm –2 and photoconversion efficiencies ( η ) of 0.116 and 0.109%, respectively, compared to values of J SC = 1.84 and 1.96 mA cm –2 and η = 0.057 and 0.051% for P1. Despite its simple dye structure, the performance of [Ru(bpy) 2 (H 5 )] parallels the best-performing cyclometallated ruthenium(II) dye in p-type DSCs reported previously (He et al , J. Phys. Chem. C , 2014, 118 , 16518) and confirms the effectiveness of a phosphonic acid anchor in the dye and the attachment of the anchoring unit to the pyridine (rather than phenyl) ring of the cyclometallating ligan

Environmental Bovine Mastitis Pathogens: Prevalence, Antimicrobial Susceptibility, and Sensitivity to Thymus vulgaris L., Thymus serpyllum L., and Origanum vulgare L. Essential Oils

Mastitis is considered to be one of the most important diseases of dairy cows in terms of health, production, and economy. Being the most common cause of antibiotic consumption in dairy cows, treatment of this disease is one of the biggest challenges in the veterinary profession as an increasing number of pathogens develop resistance to antibiotics used in the treatment. Therefore, new alternative approaches for limiting the use of antibiotics in livestock are required. For this reason, our study aimed to investigate prevalence of environmental mastitis associated bacterial strains, as well as the sensitivity of isolated strains to different antibiotics. Additionally, the therapeutic potential of three essential oils (EOs) was tested against bovine Serratia spp. and Proteus spp. mastitis pathogens, based on their chemical composition, as well as antibacterial potential. The study was carried out on 81 milk samples collected from dairy cows with mastitis. In order to determine prevalence of S. marcescens and P. mirabilis, microbiological isolation and identification were performed. Antimicrobial susceptibility testing was performed by disk diffusion method and the microdilution method was used to determine the antibacterial activity of selected EOs. In the oregano EO, a total of 23 compounds were detected, with carvacrol as a dominant component (78.94%). A total of 26 components were present in the EO of common thyme, where thymol was the most abundant compound (46.37%). Thymol also dominated (55.11%) the wild thyme EO. All tested EOs displayed antibacterial activity against all strains to different extents, while wild and common thyme EOs were the most effective. It could be concluded that the tested EOs represent promising therapeutic candidates for effective non-antibiotic treatment of mastitis