Dairy cattle breeding is one of the most important branches of livestock production, which has been facing, for several decades, the chronic problem of declining reproductive performance. In 2005, the number of cattle worldwide was about 1,370,000,000, while in 2015 that number dropped below one billion, and in 2021 it shows a slight recovery as it was 1,000,970. This indicates the importance of applying different reproductive protocols in order to increase the number of cows in production. The type of bedding on which the animals stay, as well as the characteristics of the lying area itself, shows a significant impact on numerous physiological functions such as food intake, chewing, milk yield, but also levels of sex hormones. The type of bedding and lying area, which causes chronic pain and stress, leads to disorders of physiological and reproductive processes, since stress has direct negative impact on numerous cellular functions. A total of 66 dairy cows, 50 Holstein-Friesian cows kept on PD Butmir and 16 Simmental cows kept on a private mini farm, were included in the study. At PD Butmir, cows were kept in tie-stall housing system, while on a mini-farm they were kept free. Hormonal protocols of estrus and ovulation synchronization were used in April, May and June 2019. Cows were subjected to two estrus synchronization and ovulation protocols, Ovsynch and Cosynch72. At PD Butmir, 25 cows were subjected to Ovsynch and Cosynch72 protocols, respectively. At the mini-farm only Ovsynch protocol was applied. The Ovsynch protocol applied on PD Butmir had success in conception rate of 12% (n = 3), while the Cosynch72 protocol gave a score of 36% (n = 9). On the mini-farm, Ovsynch resulted in a conception of 25% (n = 4). Based on our results, the Cosynch72 protocol, compared to the Ovsynch protocol, was a better choice in the case of Holstein-Friesian cows kept in the tie-stall housing system. In the Simmental cows kept in the free stall system, the Ovsynch protocol proved to be better choice in achieving conception, compared to the Holstein-Friesian cows. Therefore, it is necessary to test several different protocols of estrus and ovulation synchronization, in order to find the most optimal one for a certain breed, type of keeping and breeding.

Parkinson`s disease (PD) is a progressive neurodegenerative disorder involving dopaminergic neurons from the substantia nigra. The loss of dopaminergic neurons results in decreased dopamine (DA) release in the striatum and thus impaired motor functions. DA is one of the key neurotransmitters monitored for the diagnosis, and during the progression and treatment of PD. Therefore, sensitive and selective DA detection methods are of high clinical relevance. In this study, a new microfluidic device utilized for electrochemical DA detection is reported. The microfluidic sensing device operates in the range of 0.1 - 1000 nM DA requiring only ~ 2.4 µL sample volume, which corresponds to detectable 240 amol of DA. Using this sensor, we were able to monitor the changes in DA levels in cerebrospinal fluid (CSF) and plasma of a mouse model of PD and following the treatment of drug L-3,4-dihydroxyphenylalanine (L-DOPA), which reversed the parkinsonian symptoms in PD mice.

Abnormal dopamine neurotransmission is associated with several neurological and psychiatric disorders such as Parkinson's disease, schizophrenia, attention deficiency and hyperactivity disorder and addiction. Developing highly sensitive, selective and fast dopamine monitoring methods is of high importance especially for the early diagnosis of these diseases. Herein, we report a new ultrasensitive electrochemical sensing platform for in situ monitoring of cell-secreted dopamine using Au-coated arrays of micropyramid structures integrated directly into a Petri dish. This approach enables the monitoring of dopamine released from cells in real-time without need for relocating cultured cells. According to the electrochemical analyses, our dopamine sensing platform exhibits excellent analytical characteristics with a detection limit of 0.5 nM, a wide linear range of 0.01 to 500 µM, and a sensitivity of 0.18 µA/µM. The sensor also has remarkable selectivity towards DA in the presence of different potentially interfering small molecules. The developed electrochemical sensor has a great potential for in vitro analysis of neuronal cells as well as early diagnosis of different neurological diseases related to abnormal levels of dopamine.

Nanotechnology's rapid development of nanostructured materials with disruptive material properties has inspired research for their use as electrocatalysts to potentially substitute enzymes. Herein, a novel electrocatalytic nanomaterial was constructed by growing gold nanograss (AuNG) on 2D nanoassemblies of gold nanocubes (AuNC). The resulting structure (NG@NC) was used for the detection of H2O2via its electrochemical reduction. The NG@NC electrode displayed a large active surface area, resulting in improved electron transfer efficiency. On the nanoscale, AuNG maintained its structure, providing high stability and reproducibility of the sensing platform. Our nanostructured electrode showed excellent catalytic activity towards H2O2 at an applied potential of -0.5 V vs Ag/AgCl. This facilitated H2O2 detection with excellent selectivity in an environment like human urine, and a linear response from 50 µM to 30 mM, with a sensitivity of 100.66 ± 4.0 μA mM-1 cm-2. The NG@NC-based sensor hence shows great potential in nonenzymatic electrochemical sensing.

Abstract The skin, as the largest and most accessible organ in the human body, contains biofluids rich in biomarkers useful not only in diagnosis and monitoring of diseases, but also in profiling an individual’s wellbeing. Advancements in micro- and nanotechnology research have underpinned the development of multifunctional wearable sensing devices. Those sensors may allow monitoring of physiological parameters from different skin sections such as epidermis, dermis and hypodermis by sampling various bodily fluids. Our review summarizes current advances in wearable biosensors for on-skin analysis of sweat, transdermal monitoring of interstitial fluid and analysis of subcutaneous fluids via implanted devices. The review is divided into three main parts describing biosensors acting on the different skin sections. Each part focuses on recent scientific and technological advancements in the wearable biosensing field by highlighting critical challenges as well as providing information on how these barriers are being addressed by the research community.

Nowadays, there is increasing number of electrochemical biosensors which utilize chitosan (Ch); as an enzyme immobilization matrix, and conductive nanomaterials; as electron carriers improving sensitivity of the biosensor. However, the challenge these sensors face is the lack of uniform dispersion of nanomaterials throughout the Ch film, which can negatively affect analytical performance of the biosensor. In this study, we report the development of an enzyme immobilization matrix that displays enhanced electrochemical performance thanks to a novel conductive thin film prepared via in situ electrocopolymerization of pyrrole (Py) and thiophene-grafted chitosan (Th-Ch). This is a simple thin film preparation method that can help overcome aforementioned challenges by providing a uniformly distributed conductive layer on the electrode. We are also for the first time reporting the synthesis and characterization of Th-Ch, where grafted Th plays an essential role as a linking group between Ch and Py. The resulting conductive Ch-based thin film was modified with glucose oxidase (GOx) which served as a model enzyme. In situ electrocopolymerization of Py with Th-Ch resulted in a highly conductive thin film enabling approximately 40% higher sensitivity when compared to a Py-Ch composite. This new type of composite thin film is promising in biosensor technology due to its biocompatibility, the chemically and physically modifiable structure, as well as its electrical conductivity.

Cattle farming, as one of the most important branches of livestock production, has longbeen confronted with the chronic problem of the decline in reproductive performances. In 2005, thenumber of cattle around the world amounted to about 1,370,000,000 heads of cattle, while in 2012this number was just over a billion, which indicates the importance of applying differentreproductive protocols in order to increase production. Heat stress leads to disorders of thephysiological and reproductive processes, as the rise in body temperature caused by heat stress hasdirect negative consequences on numerous cell functions. The study included a total of 54 Holstein-Friesian cows, 28 experimental and 26 control cows from PD Butmir farm with 5 lactations onaverage. Hormone protocols for estrus and ovulation were used in June and July 2013. Cows in theexperimental group were subjected to a Presynch + 5dCoS2 protocol. Cows that did not conceiveafter this protocol were immediately subjected to resynchronization with Cosynch -72 protocol. Thesuccess rate of the Presynch + 5dCoS2 protocol was 19%, while in the case of Cosynch 72 it was33%, which was statistically significant (p <0,05). The first presynchronization and synchronizationprotocol (5dCoS2) did not significantly help to improve the conception rate after the firstinsemination postpartum, but it is evident that they had a positive effect on another protocol (COS72)in the form of reduction in embryonic mortality in the summer months when embryonic loss is thegreatest.The COS72 protocol provides satisfactory results in the summer, but good fitness and healthmanagement, as well as heat stress reduction in accordance with the location and farm design arethe preconditions for a successful estrus and ovulation synchronization program prior to artificialinsemination.