Division Phase Research Articles

Phytotoxic Effects of Allelochemical Acacetin on Seed Germination and Seedling Growth of Selected Vegetables and Its Potential Physiological Mechanism

Acacetin is a naturally occurring flavonoid that displays multi-pharmacological activities, as well as phytotoxicity. In this study, seeds of four typical vegetables including lettuce (Lactuca sativa L.), radish (Raphanus sativus L.), onion (Allium cepa L.) and cucumber (Cucumis sativus L.) were selected to evaluate the phytotoxic effects of acacetin, and the model plant lettuce, which is also the most sensitive species to acacetin of the four vegetables, was used to research the phytotoxic mechanism of acacetin. Bioassays showed that the germination rate and germination potential of vegetable seeds were both decreased under a high concentration of acacetin. Acacetin displayed strong inhibitory effects on root growth, shoot growth and fresh weight of vegetable seedlings in a concentration dependent manner. After treatments with acacetin, the levels of O2−, H2O2, MDA, free proline and the number of dead cells in lettuce root tips were increased, while the mitosis index (MI) was decreased. These results indicated that acacetin could cause stress on lettuce seedlings and induce the accumulation of reactive oxygen species (ROS) in plant cells, leading to lipid peroxidation and then loss of cell viability and even cell death. Moreover, acacetin influenced the mitosis of the target plant, resulting in a decreased proportion of cells during the division phase. Together, acacetin showed strongly phytotoxic effects on vegetables, and the allelopathic activity mainly depended on the influence of ROS and mitosis of the receptor plant.

Coherent Optical Frequency Transfer via a 490 km Noisy Fiber Link

We demonstrate the coherent transfer of an ultrastable optical frequency reference over a 490 km noisy field fiber link. The fiber-induced phase noise power spectrum density per-unit-length at 1 Hz offset frequency can reach up to 510 rad2⋅Hz−1⋅km−1, which is much higher than the fiber noise observed in previous reports. This extreme level of phase noise is mainly due to the fiber link laying underground along the highway. Appropriate phase-locked loop parameters are chosen to complete the active compensation of fiber noise by measuring the intensity fluctuation of additional phase noise and designing a homemade digital frequency division phase discriminator with a large phase detection range of 212 π rad. Finally, a noise suppression intensity of approximately 40 dB at 1 Hz is obtained, with fractional frequency instability of 1.1 × 10−14 at 1 s averaging time, and 3.7 × 10−19 at 10000 s. The transfer system will be used for remote atomic clock comparisons and optical frequency distribution over a long-distance communication network established in China.

Evaluation of apoptotic and anti-cancer efficacy of microwave assisted (ZnO-Ag2O) hybrid nanoparticles in MCF-7 breast cancer cell lines

The current study presents the synthesis and evaluation of zinc oxide and silver oxide hybrid nanoparticles for their potential apoptotic and anti-cancer activity. Owing to their small particle size, high surface area, and synergistic effects of embedded biomolecules, microwave-assisted synthesised nanoparticle-based drug delivery systems have significant potential in the field of biopharmaceutics and medicine. The higher activity of the hybrid nanoparticles may be attributed to their spherical shape, crystalline nature and lower particle size of 10–100 nm, as shown by different characterization methods as UV, FTIR, Zeta potential, particle size analysis, XRD, SEM, TEM, ICP-OES examination. The cell cycle analysis, cell death, and apoptosis in breast cancer cells (MCF-7) treated with synthesized hybrid NPs were evaluated in this work. Investigation of cell cycle analysis using flow cytometry has been utilized to analyse different phases of cell division and proliferation. The cytotoxic effect of microwave-assisted synthesised hybrid nanoparticles on MCF-7 cell line was studied using MTT assay and found to have significant cytotoxic activity with an IC50 value of 24.31 µg/ml when compared to standard drug Doxorubicin. Moreover, in vivo toxicity performed in Wistar rats reveals safety of developed hybrid nanoparticles. The findings demonstrate the powerful therapeutic efficacy of synthesized hybrid nanoparticles as well as the potential for development of future anticancer medication.

Antiproliferative, genotoxic and mutagenic potential of synthetic chocolate food flavoring.

Flavoring additives are of great technological importance for the food industry. However, there is little information regarding the toxicological properties of these micro-ingredients, especially at the cellular level. The present study used meristematic root cells of Allium cepa L. to evaluate the toxicity of a liquid, aroma and flavor synthetic chocolate additive, manufactured and widely marketed throughout Brazil and exported to other countries in South America. The flavoring concentrations evaluated were 100.00; 50.00; 25.00; 1.00; 0.50 and 0.25 µL/L, where the highest concentration established was one-hundred times lower than that commercially suggested for use. The concentration 100 µL/L substantially reduced cell division of meristems within 24- and 48-hours exposure. Concentrations from 100.00 to 0.50 µL/L resulted in a significant number of prophases to the detriment of the other phases of cell division, indicating an aneugenic activity, and induced a significant number of cellular changes, with emphasis on micronuclei, nuclear buds and chromosomal breaks. Under the established analysis conditions, with the exception of concentration 0.25 µL/L, the flavoring of chocolate caused cytotoxicity, genotoxicity and mutagenicity to root meristems.

Preparation of Iron Oxide and Titania-Based Composite, Core-Shell Populated, Nanoparticulates Material by Two-Step LASER Ablation in Aqueous Media as Antimicrobial and Anticancer Agents.

Iron oxide and titania-based composite nanoparticles (NPs) populated with core-shell structures, as part of the mixture of the monometallic NPs, were prepared in water medium by the two-fluence LASER ablation technique by applying 30 and 60 mJ/cm2 LASER energy irradiations. The prepared monometallics, composite, and core-shell NPs structures were confirmed from the XRD, TEM, and EDX analyses, followed by the FE-SEM and UV absorptions. Optically, the NPs exhibited an increase in the energy gap from 3.27 eV to 3.75 eV as LASER fluence increased from 30 mJ/cm2 to 60 mJ/cm2. The average NPs core size distributions for the core-shell material ranged at ∼70 nm with the shell thickness around 20 nm. The biggest NPs were of ∼170 nm size which were sparsely distributed. The magnetization behaviors of the NPs were also investigated using the vibrating sample magnetometer (VSM). The NPs showed antimicrobial activities against the pathogenic species: Escherichia coli and Staphylococcus aureus. The antimicrobial activities of the synthesized NPs, synthesized under the influence of magnetic fields, were found to be more potent than the NPs synthesized without the presence of any magnetic field. The NPs prepared under the influence of the magnetic fields also comparatively exhibited higher levels of cytotoxicity against lung cancer cell lines (A549) than the NPs prepared under no magnetic field's influence by the similar energy level effects of the LASER fluence. The flow cytometry analyses confirmed the NPs' cytotoxic impacts against the human lung cancer A549 cell lines through the initiation of apoptosis and promotion of the cell cycle arrest at the G1 phase of cell division. To further confirm the cytotoxic effects and the mechanism of the anticancer activity of the synthesized NPs against the A549 cell lines, several related parameters (cell viability, membrane permeability, nuclear intensity, and cytochrome-C release) were analyzed using the high-content screening (HCS) assay. The study suggested that the prepared NPs have potential as antimicrobial and also as anti-lung-cancer agents as tested in vitro. These NPs can also be part of combined chemotherapy in different oncological interventions, as well as a sonosensitizer in sonomagnetic heating-based therapy, especially for cancers.

Divide well to merge better: A novel clustering algorithm

In this paper, a novel non-parametric clustering algorithm which is based on the concept of divide-and-merge is proposed. The proposed algorithm is based on two primary phases, after data cleaning: (i) the Division phase and (ii) the Merging phase. In the initial phase of division, the data is divided into an optimized number of small sub-clusters utilizing all the dimensions of the data. In the second phase of merging, the small sub-clusters obtained as a result of division are merged according to an advanced statistical metric to form the actual clusters in the data. The proposed algorithm has the following merits: (i) ability to discover both convex and non-convex shaped clusters, (ii) ability to discover clusters different in densities, (iii) ability to detect and remove outliers/noise in the data (iv) easily tunable or fixed hyperparameters (v) and its usability for high dimensional data. The proposed algorithm is extensively tested on 20 benchmark datasets including both, the synthetic and the real datasets and is found better/competing to the existing state-of-the-art parametric and non-parametric clustering algorithms.

Fruit size control by a zinc finger protein regulating pericarp cell size in tomato

Fruit size is largely defined by the number and size of cells in the fruit. Endoreduplication – a specialized cell cycle – is highly associated with cell expansion during tomato fruit growth. However, how endoreduplication coupled with cell size is regulated remains poorly understood. In this study, we identified a zinc finger gene SlPZF1 (SolanumlycopersicumPERICARP-ASSOCIATEDZINCFINGER PROTEIN 1) that was highly expressed in the pericarp of developing fruits. Plants with altered SlPZF1 expression produced smaller fruits due to the reduction in cell size associated with weakened endoreduplication. Overexpressing SlPZF1 delayed cell division phase by enhancing early expression of several key cell cycle regulators including SlCYCD3;1 and two plant specific mitotic cyclin-dependent protein kinase (SlCDKB1 and SlCDKB2) in the pericarp tissue. Furthermore, we identified 14 putative SlPZF1 interacting proteins (PZFIs) via yeast two hybrid screening. Several PZFIs, including Pre-mRNA-splicing factor (SlSMP1/PZFI4), PAPA-1-like conserved region family protein (PZFI6), Fanconi anemia complex components (PZFI3 and PZFI10) and bHLH transcription factor LONESOME HIGHWAY (SlLHW/PZFI14), are putatively involved in cell cycle regulation. Our results demonstrate that fruit growth in tomato requires balanced expression of the novel cell size regulator SlPZF1.

The influence of severity and time of foliar damage on yield and fruit quality in apple (Malus domestica Borkh.)

Leaf damage/defoliation caused by pests or phytotoxic damage following chemical application can result in loss of leaf area at any time during the growing season. Four trials were conducted to examine the impact of severity and time of foliar damage on fruit set and quality in apple. Trees tolerated light to moderate leaf damage throughout the season with no significant effect on fruit set and thus crop load. Where 75% or more of the leaf surface was lost, fruit set was reduced and fruit quality was affected. Complete loss of leaves up to three weeks after full bloom (wAFB) resulted in very low or no fruit set, but from 9 wAFB crop load was not affected by leaf damage. Loss of terminal shoot leaves had no effect on fruit set, but spur leaves were critical early in the season with the impact lessening from 6 wAFB. This study has demonstrated that low levels of foliar damage have little effect on fruit size or quality, but high levels can impact on both set and quality. Fruit quality was reduced following leaf damage during the period 6–12 weeks after full bloom which is the critical period for cell division in the fruit as well as flower initiation for the following year. High levels of leaf damage also reduced fruit size in spite of reduced crop load levels, most likely the result of a reduction in carbohydrate assimilation during the cell division phase of fruit development.

Maintaining the proliferative cell niche in multicellular models of epithelia

The maintenance of the proliferative cell niche is critical to epithelial tissue morphology and function. In this paper we investigate how current modelling methods can result in the erroneous loss of proliferative cells from the proliferative cell niche. Using an established model of the inter-follicular epidermis we find there is a limit to the proliferative cell densities that can be maintained in the basal layer (the niche) if we do not include additional mechanisms to stop the loss of proliferative cells from the niche. We suggest a new methodology that enables maintenance of a desired homeostatic population of proliferative cells in the niche: a rotational force is applied to the two daughter cells during the mitotic phase of division to enforce a particular division direction. We demonstrate that this new methodology achieves this goal. This methodology reflects the regulation of the orientation of cell division.

Unsupervised tensor decomposition-based method to extract candidate transcription factors as histone modification bookmarks in post-mitotic transcriptional reactivation.

The histone group added to a gene sequence must be removed during mitosis to halt transcription during the DNA replication stage of the cell cycle. However, the detailed mechanism of this transcription regulation remains unclear. In particular, it is not realistic to reconstruct all appropriate histone modifications throughout the genome from scratch after mitosis. Thus, it is reasonable to assume that there might be a type of “bookmark” that retains the positions of histone modifications, which can be readily restored after mitosis. We developed a novel computational approach comprising tensor decomposition (TD)-based unsupervised feature extraction (FE) to identify transcription factors (TFs) that bind to genes associated with reactivated histone modifications as candidate histone bookmarks. To the best of our knowledge, this is the first application of TD-based unsupervised FE to the cell division context and phases pertaining to the cell cycle in general. The candidate TFs identified with this approach were functionally related to cell division, suggesting the suitability of this method and the potential of the identified TFs as bookmarks for histone modification during mitosis.

Inhibition of ALDH1A1 Activity in Cisplatin-Resistant Ovarian Cancer Cells Alters Their Cancer Stemness, Cell Cycle Profile and Mitochondrial Respiration Rate

Introduction: Ovarian cancer is one of the leading cause of morbidity and death among women, with a five-year relative survival rate of only 30% in patients diagnosed with distant metastasis. The ovarian cancer cells initially respond to first-line platinum drug cisplatin [cis-diamminedichloroplatinum(II) (CDDP)] treatment. But, they subsequently develop resistance to CDDP and eventually exhibit chemoresistance. Aldehyde dehydrogenase 1 family member A1 (ALDH1A1) is one of the key functional markers of ovarian cancer stem cells (CSCs) that confers cancer stemness and therapeutic resistance, and is associated with poor prognosis and patient survival. In this study, we have assessed the anticancer effects of the ALDH1A1 inhibitor, A37, in CDDP-resistant ovarian cancer cells in vitro. Experimental Methods: SK-OV-3-CDDP, cisplatin-resistant ovarian cancer cells were treated with different concentrations of the small molecule inhibitor of ALDH1A1, A37. We determined the cell proliferation using water-soluble tetrazolium salt (WST-1) assay at 24 and 48 h. The distribution of cell division phases by cell cycle analysis and oxygen consumption rate (OCR) via seahorse extracellular flux analysis were assessed by flow cytometry and seahorse XFe24 analyzer, respectively. Furthermore, we examined the protein expression of key signaling molecules by western blot analysis and cancer stemness by tumorsphere formation assay. Results: Treatment of SK-OV-3-CDDP cells with A37 significantly reduced the ovarian cancer cell proliferation. Interestingly, A37 induced cell cycle arrest as observed by an increase in G1 phase of the cell cycle. Additionally, A37 reduced the mitochondrial respiration of ovarian cancer cells as observed by the decrease in basal OCR. Moreover, A37 treatment markedly decreased the expression of WW domain containing transcription regulator 1 (WWTR1) protein [also called as transcriptional co-activator with PDZ-binding motif (TAZ)], which is a key downstream effector of mammalian Hippo signaling pathway that promotes cancer stemness, metastasis and chemoresistance. Importantly, A37 reduced the number and size of the tumorspheres. Conclusions: Our study suggests that inhibiting the ALDH1A1 activity using A37 reduced the cell proliferation and induced cell cycle arrest in CDPP-resistant ovarian cancer cells. The mechanism by which A37 elicits its anticancer effects on ovarian cancer cells include impairment in mitochondrial respiration that could alter cancer cell metabolism, and a decrease in WWTR1/TAZ expression and tumorsphere formation that could suppress cancer stemness. Our findings demonstrate that inhibition of ALDH1A1 could effectively eliminate the chemoresistant ovarian cancer cells, and therefore, new strategies targeting ALDH1A1 could lead to the development of novel therapeutics for aggressive chemoresistant ovarian cancer.

Control of pre-replicative complex during the division cycle in Chlamydomonas reinhardtii.

DNA replication is fundamental to all living organisms. In yeast and animals, it is triggered by an assembly of pre-replicative complex including ORC, CDC6 and MCMs. Cyclin Dependent Kinase (CDK) regulates both assembly and firing of the pre-replicative complex. We tested temperature-sensitive mutants blocking Chlamydomonas DNA replication. The mutants were partially or completely defective in DNA replication and did not produce mitotic spindles. After a long G1, wild type Chlamydomonas cells enter a division phase when it undergoes multiple rapid synchronous divisions (‘multiple fission’). Using tagged transgenic strains, we found that MCM4 and MCM6 were localized to the nucleus throughout the entire multiple fission division cycle, except for transient cytoplasmic localization during each mitosis. Chlamydomonas CDC6 was transiently localized in nucleus in early division cycles. CDC6 protein levels were very low, probably due to proteasomal degradation. CDC6 levels were severely reduced by inactivation of CDKA1 (CDK1 ortholog) but not the plant-specific CDKB1. Proteasome inhibition did not detectably increase CDC6 levels in the cdka1 mutant, suggesting that CDKA1 might upregulate CDC6 at the transcriptional level. All of the DNA replication proteins tested were essentially undetectable until late G1. They accumulated specifically during multiple fission and then were degraded as cells completed their terminal divisions. We speculate that loading of origins with the MCM helicase may not occur until the end of the long G1, unlike in the budding yeast system. We also developed a simple assay for salt-resistant chromatin binding of MCM4, and found that tight MCM4 loading was dependent on ORC1, CDC6 and MCM6, but not on RNR1 or CDKB1. These results provide a microbial framework for approaching replication control in the plant kingdom.

Microbe Profile: Bdellovibrio bacteriovorus: a specialized bacterial predator of bacteria.

Bdellovibrio bacteriovorus is an environmentally-ubiquitous bacterium that uses unique adaptations to kill other bacteria. The best-characterized strain, HD100, has a multistage lifestyle, with both a free-living attack phase and an intraperiplasmic growth and division phase inside the prey cell. Advances in understanding the basic biology and regulation of predation processes are paving the way for future potential therapeutic and bioremediation applications of this unusual bacterium.

Revisiting poly(A)-binding proteins: Multifaceted regulators during gametogenesis and early embryogenesis.

Post-transcriptional regulation faces adistinctivechallenge in gametes. Transcription is limited when the germ cells enter the division phase due to condensed chromatin, while gene expression during gamete maturation, fertilization, and early cleavage depends on existing mRNA post-transcriptional coordination. The dynamics of the 3'-poly(A) tail play crucial roles in defining mRNA fate. The 3'-poly(A) tail is covered with poly(A)-binding proteins (PABPs) that help to mediate mRNA metabolism and recent work has shed light on the number and function of germ cell-specific expressed PABPs. There are two structurally different PABP groups distinguished by their cytoplasmic and nuclear localization. Both lack catalytic activity but are coupled with various roles through their interaction with multifunctional partners during mRNA metabolism. Here, we present a synopsis of PABP function during gametogenesis and early embryogenesis and describe both conventional and current models of the functions and regulation of PABPs, with an emphasis on the physiological significance of how germ cell-specific PABPs potentially affect human fertility.

Association of DNAbiosynthesiswith planting value enhancement in hydroprimed maize seeds.

Inadequate plant stand establishment due to insufficient germination is an important bottleneck in achieving the potential yields, specifically under uncertain growing conditions. Hydropriming has been publicized as a useful tool to alleviate the stress-induced consequences. Association of DNA biosynthesis in hydroprimed seeds of maize; hybrid, PEHM 5 and its parental lines (CM150 and CM151) was studied. Seeds were hydroprimed at 25 °C for 30 h and half of them were surface dried while the other half were redried back to the original moisture contents. The treated and untreated seeds were evaluated for; germination test, mean germination time, vigour index and DNA levels in embryos of fully matured seeds. Both the treatment strategies significantly enhanced the planting value of maize seeds. Vigour index I revealed significant correlation with G2/G1 ratio whereas significant negative correlation between G2/G1 ratio and mean germination time was observed. Large amounts of 2C DNA signals in flow cytometric analysis divulged that most cells might had arrested in the cell cycle at the pre synthetic G1 phase of nuclear division. Augmentation of 4C signal in the embryonic region was noticed after imbibition that could be ascribed to cells entering the synthetic phase of nuclear division. The embryonic cells showed increased 4C:2C ratios after 30 h of imbibition. Apparently, DNA synthesis preceded germination. In dry seeds, DNA histograms revealed both a 2C signal and a considerable 4C peak. A priming period of 30 h in distilled water considerably enhanced the rate and uniformity of germination in both surface dried and redried treatment strategies. Upon priming, the ratio of 4C:2C increased during the 30 h priming period, though the level in case of redried seeds did not reach the level obtained after hydration in water without drying back. However, the 4C: 2C ratio was constant after redrying the seeds to the original moisture content, indicating that the chromosomal material in the embryonic cells had stably ceased cell cycle activity at the G2 phase. The present results indicate that the beneficial effects of priming on seedling performance could be associated with the action of replicative DNA synthesis processes prior to germination.

Effects of water deficit on leaves and fruit quality during the development period in tomato plant.

In nature, plants are often exposed to a multitude of environmental constraints that severely limit crop productivity. Water deficit is one of the factors that most affects agricultural production. The aim of this work is to evaluate the effect of water deficit on morphology, development, nutritional behavior, as well as chlorophyll fluorescence and certain important metabolic parameters (soluble sugars, organic acids, starch, carotenoid, and vitamin C) of the cultivated tomato (Solanum lycopersicum cv Plovdiv). In this study, the water supply was reduced by 60% compared to control conditions. The conditions of water deficit showed that the size of the different organs (leaves, fruits) was reduced. A reduction in the number, width, and length of the leaves, respectively, 9%, 36%, and 37%, then the leaf surface was also observed. Reduction of fluorescence (Fo, Fm, and Fv) and total index performance were among the other symptoms of plants with water deficiency. For fruit, we observed a significant decrease in diameter, fresh weight, and moisture content during the cell division period, the cell expansion period, and the fruit ripening period. In contrast, the composition of the Plovdiv fruit changed only during cell division and expansion phase. On the other hand, the water deficit induces an increase in the total carotenoid and vitamin C content of the fruits.. Besides, water deficit induced a reduction of fruit size, moisture content, and production dry matter during different phases of development. Decrease levels of soluble sugars and organic acid but increase in vitamin C and carotenoid content.

Time-motion analysis in elite female Wushu Sanda athletes according to competitive phases and weight categories

Introduction: Wushu Sanda is a Chinese combat sport. Objective: To measure the time-motion structure of elite female wushu sanda athletes during the 13th World Wushu Championships in different weight divisions (light, middle, and heavy categories) and competition phases (eliminatory, quarterfinals, semifinals and finals). Material and methods: Fifty-five female athletes from 31 countries participated in 46 matches during the competition. All 46 matches, accounting 95 rounds, 35 in light, 25 in middle and 35 in heavyweight divisions, took part in the study. Matches were analyzed using the software Kinovea™. Each match was reproduced in slow motion (50%) twice; therefore, one athlete was observed each time to ensure that all activities would be registered, totalizing 92 observations (46 matches, 2 observations per match). We registered the time in observation, preparation, interaction, effort, pause, high-intensity and low-intensity activities. Results: Descriptive data showed an effort:pause ratio of 2.2:1, a high:low intensity efforts ratio of 1:1.3, and mean observation-preparation-interaction times of 4.5-1.2-4.2 seconds. When comparing by weight category, heavyweight categories had higher total fighting time per round than the light and middle categories. Also, heavyweight categories had longer preparation and interaction mean-time; and referee interruption time frequency, total and mean times than the light and middle categories. Total pause time was also higher for heavyweights. According to the competitive phase, semifinal matches had shorter observation times than eliminatory and final matches. Also, semifinal matches had lower low-intensity time than quarterfinals and finals. Conclusions: Wushu sanda is an intermittent combat sport, and female athletes present some time-motion differences according to weight division and competitive phase.

Nuclear localization of BCR and cortactin indicates their potential role in regulation of actin branching in nucleus.

To study cellular localization of full-length breakpoint cluster region (BCR), Pleckstrin homology domain of BCR and cortactin and determine whether they can coexist in cell nucleus. HEK293T cell line was transfected with pECFP-BCR, pEGFP-PH and pmTagRFP-N1-CTTN using polyethyleneimine. Live cells were imaged in cell culture dishes with glass coverslip attached to the bottom with Leica SP8 STED 3D confocal microscope in the environmental chamber. Obtained images were processed and analyzed with Fiji software. We identified colocalization of full-length BCR and cortactin in nucleus of cell undergoing terminal phase of cell division. We did not observe nuclear localization of cortactin in non-dividing cell. Both Pleckstrin homology domain and full-length BCR exhibited cytoplasmic as well as nuclear localization. Colocalization of BCR with cortactin in cell nucleus indicates their potential role in regulation of actin network allowing for the maintenance of nuclear architecture and DNA integrity.

A Phase Distribution Network Using 2 × 4 Butler Matrix for Linear/Planar Beam-Scanning Arrays

A new $1\times $ 4 phase distribution network (PDN) featuring a fully controllable progressive phase shift between outputs is proposed for continuous beam-scanning arrays. The PDN is made up of two parts: a modified $2\times $ 4 Butler matrix integrated with four phase shifters (PSs), and a tunable power divider (TPD) whose power division ratio can be controlled over a wide tuning range. The synthesis equations show that the relative phase shift between PDN outputs can be fully controlled by the TPD and embedded PSs without using an external single-pole quad-throw (SP4T) switch. The proposed PDN is demonstrated at 2.4 GHz as the feed network of a 4-element linear array. The experimental results display a fully controllable progressive phase shift (from −180° to 180°) between PDN outputs over a 20% bandwidth with good performance of matching, power division, and relative phase shifts. A spatial coverage of 116° with the feature of continuous beam scanning and negligible dc power consumption is achieved. Benefitting from the single-input topology, a planar 16-element phased array for 2D beam scanning is then realized by simply stacking and cascading five instead of eight PDN modules. It removes the high-cost and bulky SP16T switch. Experimental results demonstrate the uniqueness of the proposed designs.

Principles and rationale of infusion therapy in tuberculosis

Background. In 2018 7 million new cases of tuberculosis (TB) were registered, which is more than in previous years. Undoubtedly, TB is one of the most important threats to the public health globally. In developing countries, where there are no new TB drugs (TBD) and modern medical services, this threat is even more serious. Intravenous administration is an option to optimize the existing drug regimens, as it is accompanied by increased bioavailability.
 Objective. To substantiate the rationality of infusion therapy in TB.
 Materials and methods. Analysis of literature data on this topic; own study involving 106 patients with newly diagnosed infiltrative and disseminated pulmonary TB with bacterial excretion.
 Results and discussion. The medical community is concerned not only about the increase in the TB incidence, but also about the increase in the number of drug resistance (DR) cases. Improper treatment is one of the causes of DR. In case of oral administration absorption disorders of the drug are possible in people with digestive system diseases, in addition, part of the drug is metabolized by passing through the liver. In contrast, intravenous drugs enter the superior vena cava system, right ventricle, and pulmonary arteries. In a number of patients’ subgroups, it is not possible to achieve a sufficient concentration of drugs in serum when taken orally for various reasons. In particular, these reasons include host organism factors (features of drug metabolism (fast acetylators are more likely to have DR than slow ones), malabsorption, drug clearance, inability of the drug to reach lung tissue) and mycobacteria factors (biofilm formation, drug resistance due to efflux pumps, metabolic status of the bacterium – division phase or sleep phase). These factors are considered to be the consequences of continuous oral administration of TBD. Achieving a high concentration of TBD in the source of infection due to intravenous administration allows to overcome the DR of mycobacteria. In the own study, oral (n=33) and intravenous (n=73) modes of TBD administration were compared. The groups were identical in age, sex, and TB stage. In the intravenous treatment group there was a significantly higher proportion of complete closure of the decay cavities (90.5 % vs. 60.4 % in the oral treatment group; p=0.04), as well as the significantly lower number of toxic reactions (14.3 % vs. 57.9 %; p=0.001) and poor tolerability of treatment (31 % vs. 57.9 %; p=0.04). On the background of intravenous therapy less fluoroquinolone DR was observed.
 Conclusions. 1. Intravenous therapy in patients with pulmonary TB is more effective than standard in terms of closure of the decay cavities. 2. Intravenous therapy is accompanied by significantly less toxicity and better tolerability. 3. Intravenous TB therapy is less likely to provoke the development of DR.