Liquid Crystal Dimers and the Twist-Bend Phases: Non-Symmetric Dimers Consisting of Mesogenic Units of Differing Lengths.

The syntheses and characterisation of the 4-[{[4-({n-[4-(4-cyanophenyl)phenyl]-n-yl}oxy)phenyl]-methylidene}amino]phenyl-4-alkoxybenzoates (CBnOIBeOm) are reported with n=8 and 10 and m=1-10. The two series display fascinating liquid crystal polymorphism. All twenty reported homologues display an enantiotropic nematic (N) phase at high temperature. When the length of the spacer (n) is greater than that of the terminal chain (m), the twist-bend nematic (NTB) phase is observed at temperatures below the N phase. As the length of the terminal chain is increased and extends beyond the length of the spacer up to three smectic phases are observed on cooling the N phase. One of these smectic phases has been assigned as the rare twist-bend smectic C subphase, the SmCTB-α phase. In all the smectic phases, a monolayer packing arrangement is seen, and this is attributed to the anti-parallel associations of the like mesogenic units.

To Be or Not To Be Polar: The Ferroelectric and Antiferroelectric Nematic Phases.

We report two new series of compounds that show the ferroelectric nematic, NF, phase in which the terminal chain length is varied. The longer the terminal chain, the weaker the dipole-dipole interactions of the molecules are along the director and thus the lower the temperature at which the axially polar NF phase is formed. For homologues of intermediate chain lengths, between the non-polar and ferroelectric nematic phases, a wide temperature range nematic phase emerges with antiferroelectric character. The size of the antiparallel ferroelectric domains critically increases upon transition to the NF phase. In dielectric studies, both collective ("ferroelectric") and non-collective fluctuations are present, and the "ferroelectric" mode softens weakly at the N-NX phase transition because the polar order in this phase is weak. The transition to the NF phase is characterized by a much stronger lowering of the mode relaxation frequency and an increase in its strength, and a typical critical behavior is observed.

Using Lateral Substitution to Control Conformational Preference and Phase Behaviour of Benzanilide-based Liquid Crystal Dimers.

The inclusion of secondary and tertiary benzanilide-based mesogenic groups into liquid crystal dimers is reported as a means to develop new materials. Furthermore, substitution at the nitrogen atom is shown to introduce an additional synthetic 'handle' to modify the molecular structure of the tertiary materials. The design of these materials has proved challenging due to the strong preferences of 3° benzanilides for the E amide conformation. In this work, lateral substitution is used to modify the conformational preferences of the amide linkage and promote liquid crystallinity for a series of N-methyl benzanilide dimers. As the proportion of the E conformer decreases, the nematic-isotropic transition temperatures increase, and enantiotropic nematic behaviour is observed. We also report the synthesis and characterisation of the analogous 2° benzanilide-based materials, which show nematic and twist-bend nematic behaviour. This approach highlights the effects that seemingly small structural modifications, such as the inclusion and position of a methyl group, can have on molecular shape and hence, liquid crystalline behaviour.

Multiple Polar and Non-polar Nematic Phases.

Liquid-crystal materials exhibiting up to three nematic phases are reported. Dielectric response measurements show that while the lower temperature nematic phase has ferroelectric order and the highest temperature nematic phase is apolar, the intermediate phase has local antiferroelectric order. The modification of the molecular structure by increasing the number of lateral fluorine substituents leads to one of the materials showing a direct isotropic-ferronematic phase transition.

Photonic Bandgap in Achiral Liquid Crystals-A Twist on a Twist.

Achiral mesogenic molecules are shown to be able to spontaneously assemble into liquid crystalline smectic phases having either simple or double-helical structures. At the transition between these phases, the double-helical structure unwinds. As a consequence, in some temperature range, the pitch of the helix becomes comparable to the wavelength of visible light and the selective reflection of light in the visible range is observed. The photonic bandgap phenomenon is reported for achiral liquid crystals.

Twist-Bend Nematic Glasses: The Synthesis and Characterisation of Pyrene-based Nonsymmetric Dimers.

A selection of pyrene-based liquid crystal dimers have been prepared, containing either methylene-ether or diether linked spacers of varying length and parity. All the diether linked materials, CBOnO.Py (n=5, 6, 11, 12), exhibit conventional nematic and smectic A phases, with the exception of CBO11O.Py which is exclusively nematic. The methylene-ether linked dimer, CBnO.Py, with an even-membered spacer (n=5) was solely nematogenic, but odd-members (n=6, 8, 10) exhibited both nematic and twist-bend nematic phases. Replacement of the cyanobiphenyl fragment by cyanoterphenyl giving CT6O.Py, gave elevated melting and nematic-isotropic transition temperatures, and SmA and SmCA phases were observed on cooling the nematic phase. Intermolecular face-to-face associations of the pyrene moieties drive glass formation, and all these materials have a glass transition temperature at or above room temperature. The stability of the glassy twist-bend nematic phase allowed for its study using AFM, and the helical pitch length, PTB , was measured as 6.3 and 6.7 nm for CB6O.Py and CB8O.Py, respectively. These values are comparable to the shortest pitch of a twist-bend nematic phase measured to date.

Risk factors of suicide with reference to the theory of social integration by Émile Durkheim. / Czynniki ryzyka samobójstwa w kontekscie teorii integracji spolecznej wedlug Émile'a Durkheima.

AIM: The aim of the paper was to: (1) present economic, socio-demographic and other indicators related to suicide, useful from the perspective of social integration theory, and (2) identify new indicators of special importance to contemporary Poland. METHOD: A narrative literature review on the sociological approach to suicide was undertaken by searching MEDLINE/PubMed, PsycINFO, Google Scholar databases using the following key words: suicide, suicide risk factors, Durkheim's theory of suicide, integration and disintegration of society, sociodemographic factors, economic factors, religion, and the time descriptors: 2000-2017. RESULTS: Suicide risk was analyzed in relation to: family integration (including the rates of divorce, marriage, fertility, and women's participation in the labour market); economy (including the unemployment rate, gross domestic product per capita, Gini social inequality index, and social welfare indicators); social issues (including the indicators of the healthcare system quality, the rates of alcohol consumption per capita and migration); religion (including the parameters of conventional religiosity, Gallup index, and percentage of religious books). The issues relevant for Poland were addressed while discussing Balanced Development Index in economic aspect, and dominicantes and communicantes rates in religious aspect. CONCLUSIONS: This literature review may be useful in the assessment of suicide risk when designing suicide prevention programs and for mental health clinicians in their daily practice.

Yolk proteins in the male reproductive system of the fruit fly Drosophila melanogaster: spatial and temporal patterns of expression.

In insects, spermatozoa develop in the testes as clones of single spermatogonia covered by specialized somatic cyst cells (cc). Upon completion of spermatogenesis, spermatozoa are released to the vas deferens, while the cc remain in the testes and die. In the fruit fly Drosophila melanogaster, the released spermatozoa first reach the seminal vesicles (SV), the organ where post-testicular maturation begins. Here, we demonstrate the temporal (restricted to the evening and early night hours) accumulation of membranous vesicles containing proteins in the SV lumen of D. melanogaster. When SV vesicles were isolated from the semen and co-incubated with testis-derived spermatozoa in vitro, their contents bound to the spermatozoa along their tails. The proteins of the SV vesicles were then characterized using 2-D electrophoresis. We identified a prominent protein spot of around 45-47 kDa, which disappears from the SV vesicles in the night, i.e. shortly after they appear in the SV lumen. Sequencing of peptides derived from this spot by mass spectrometry revealed identity with three yolk proteins (YP1-3). This unexpected result was confirmed by western blotting, which demonstrated that SV vesicles contain proteins that are immunoreactive with an antibody against D. melanogaster YP1-3. The expression of all yp genes was shown to be a unique feature of testis tissues. Using RNA probes we found that their transcripts localize exclusively to the cc that cover fully developed spermatozoa in the distal part of each testis. Temporally, the expression of yp genes was found to be restricted to a short period during the day and is followed by the evening accumulation of YP proteins in the cc. Immunohistochemical staining confirmed that cc are the source of SV vesicles containing YPs that are released into the SV lumen. These vesicles interact with spermatozoa and as a result, YPs become extrinsic proteins of the sperm membrane. Thus, we describe for the first time the expression of yolk proteins in the male reproductive system of D. melanogaster under physiological conditions, and show that somatic cells of the testes are the source of these proteins.

Cell cycle-dependent modulations of fenestrin expression in Tetrahymena pyriformis.

In Tetrahymena, besides apparent cell polarity generated by specialized cortical structures, several proteins display a specific asymmetric distribution suggesting their involvement in the generation and the maintenance of cell polarization. One of these proteins, a membrane skeleton protein called fenestrin, forms an antero-posterior gradient, and is accepted as a marker of cell polarity during different cellular processes, such as cell division or oral replacement. In conjugating cells, fenestrin forms an intracytoplasmic net which participates in pronuclear exchange. The function of fenestrin is still unknown. To better understand the role of fenestrin we characterized this protein in an amicronuclear Tetrahymena pyriformis. We show that in this ciliate not only does fenestrin localization change in a cell division-dependent manner, but its mRNA and protein level is also cell cycle-regulated. We determine that the two available anti-fenestrin antibodies, 3A7 and 9A7, recognize different pools of fenestrin isoforms, and that 9A7 is the more general. In addition, our results indicate that fenestrin is a phosphoprotein. We also show that the level of fenestrin in the amicronuclear T. pyriformis and the amicronuclear BI3840 strain of T. thermophila is several times lower than in micronuclear T. thermophila.

Microbiologically active Mannich bases derived from 1,2,4-triazoles. The effect of C-5 substituent on antibacterial activity.

Our research proved that chemical character of the C-5 substituent significantly determines the antibacterial activity of the Mannich bases derived from 4,5-disubstituted 1,2,4-triazole-3-thiones. This activity was considerably increased by an introduction of a chlorine atom to the phenyl ring. The obtained compounds were particularly active against opportunistic bacteria (Bacillus subtilis and Bacilluscereus). The antibacterial activity of some Mannich bases was similar or higher than the activity of commonly used antibiotics such as ampicillin and cefuroxime.

[Transient and permanent damage to the heart in the course of acute poisoning]. / Przemijajace i trwale uszkodzenia serca w przebiegu ostrych zatruc.

Transient and permanent myocardial damage is a vital element of toxicological practice. This applies both to poisonings in which heart injury is typical and to those in which it is only a rare complication. Vital signs of poisoned patients, especially unconscious ones, must be carefully monitored, because the consequences of late diagnosis or improper treatment can be potentially fatal. The following paper discusses the mechanisms leading to heart damage in the course of acute poisoning. It also presents clinical symptoms, treatment options and prognosis for myocardial injury in selected poisonings.

[Heart injury secondary to carbon monoxide poisoning--the use of imaging techniques]. / Uszkodzenie serca w przebiegu zatrucia tlenkiem wegla--zastosowanie badan obrazowych.

The heart muscle is particularly sensitive to the toxic effects of carbon monoxide. Cardiovascular complications are present in 30-40% poisoned patients. Currently, multiple ECG records and at least two-time determination of cardiac markers' concentration (mainly troponin I) are known as the gold standard practice in the diagnosis of cardiac injury especially with regard to medium and severe poisoning. So far there have not been any recommendations for further diagnostic steps in case of abnormalities in these examinations. This paper presents a review of cardiac imaging techniques as well as the analysis of their usefulness in carbon monoxide poisoning. According to the authors echocardiography is considered to be an extremely important examination which, thanks to its accessibility and non-invasive nature, should be performed on all patients with myocardium injury suspicion made on the basis of clinical image, ECG records and biochemical markers.

[Myocardial injury in the course of carbon monoxide poisoning]. / Uszkodzenie miesnia sercowego w przebiegu zatrucia tlenkiem wegla.

Carbon monoxide still remains one of the most common causes of fatal poisonings. Mechanisms of carbon monoxide toxic effects are complex and lead to hypoxia of body tissues. The most sensitive to tissue hypoxia are: the central nervous system and the cardiovascular system.The most characteristic cardiac symptoms of carbon monoxide poisoning are: stenocardial symptoms, hypotonia, myocardial dysfunction and arrhythmia (atrial fibrillation, tachycardia, bradycardia). Carbon monoxide connects with high affinity to metallo-proteins mainly to hemoglobin impairing oxygen transport in the body and to myoglobin, interfering with its function as oxygen reservoir among others in myocardium. Connecting to cytochrome oxidase in mitochondria it blocks the chain of electron transport which results in impairment of cellural respiration and formation of free radicals. Carbon monoxide has also relaxation effect against the smooth muscles of blood vessels, and thrombogenic effect. It is particularly adverse in patients with ischemic heart disease. In case of carbon monoxide poisoning one should always search for features of myocardial injury- as far as screening is concerned the most important ones are ECG and screening for cardiac troponin. Depending on the course of poisoning other laboratory (e.g. BNP) or imaging (echo-cardiography. scintiscanning, coronarography) tests may also prove to be useful.

[Silibinin and its hepatoprotective action from the perspective of a toxicologist]. / Sylibinina i jej dzialanie hepatoprotekcyjne z punktu widzenia toksykologa.

Silibinin is the most active component of a complex of flavonoids -silymarin contained in fruit milk thistle (Sylibum marianum). Its mechanism of action is complex and highly beneficial in protecting hepatocytes. On the one hand this compound blocks the penetration of various toxins (for example amanitin) into the hepatocytes not allowing in this way for the cell death and on the other hand, it prevents apoptosis through intracellular. It protects the liver from oxidative intracellular free radicals by increasing the activity of enzyme superoxide dismutase and peroxidase, as well as by increasing the concentration of glutathione and the activity of the peroxidase. Silibinin strengthens and stabilizes the cell membranes, inhibits the synthesis of prostaglandins associated with the lipid peroxidation and promotes regeneration of liver through the stimulation of protein synthesis and effect on the production of new hepatocytes. A particularly interesting topic from the perspective of a toxicologist is the application of silibinin in Amanita phalloides poisoning. Clinical trials conducted in this respect are very encouraging. The other beneficial application of silibinin is in therapy of the alcoholic liver cirrhosis. The evidence shows that the use of silymarin leads to a significant reduction in liver-related mortality and even reduction in the number of patients with encephalopathy in the course of the disease. Application of silibinin goes beyond liver disease and expands in the direction of cancer and even diabetes. What is interesting is the fact, that the substance of herbal origin occurring in the environment is so strong, favorable, beneficial and multidirectional. Science has contributed to improving the bioavailability of silibinin thus making it more effective.

[Gamma-hydroxybutyrate (GHB) and its lactone (GBL) as psychoactive substances]. / Kwas gamma-hydroksymaslowy (GHB) i jego lakton (GBL) jako substancje psychoaktywne.

Gammabutyrolactone is included in the solvent such as wheel cleaners, pesticides, cosmetics, drugs. After ingestion GBL is converted to gamma-hydroxybutyrate. Both substances are classified as so called "club drugs" and their action is characterized by euphoria, sedation, and induction of retrograde amnesia of events. These activities were basis for the use of GHB and its lactone as rape pill. Acute poisoning with these compounds causes confusion, agitation, ataxia, nausea, vomiting, nystagmus, dyskinesia, hallucinations, coma, irregular breathing, hypothermia, bradycardia, hypotension, convulsions, respiratory paralysis and thus respiratory arrest. These substances carry a risk of development of physical addiction of the hard proceeding of abstinence syndrome. In the USA there is a ban on the sale and promotion of these compounds. In Poland despite the fact that GHB is a controlled substance, there is no regulation of GBL trading. The aim of this paper is to summarize current knowledge regarding the pharmacology, impact on the human body, toxicity, and the effects of chronic abuse of these substances.

[Sodium azide poisoning--a rare reason of hospitalization in toxicological units--case report]. / Zatrucie azydkiem sodu--rzadka przyczyna hospitalizacji w osrodkach toksykologicznych--opis przypadku.

Sodium azide poisonings are a rare reason for hospitalization in toxicological units. They are observed as rarely as once within a number of years per hospital. Consequently, an algorithm for the optimum procedure of treating such intoxications does not exist and, as a result, there is a need to describe every single clinical case. A female, aged 55, was directed to the toxicological unit from a county hospital after swallowing four tablets of sodium azide, 150 mg each, in the form of preservative for fresh milk samples. Two hours after the incident a gastric lavage was performed and the tableting blend was retrieved. In the clinical examination higher concentration of lactic acid, ALAT and TSH were observed. In the ECG record unspecific aberrations in the ST segment were noticed. Due to the patient's general good condition and the fact that the tableting blend had been retrieved from the gastric rinse, further use of the antidote indicated in the therapy of cyanide intoxications was abandoned. Symptomatic treatment was used along with the patient's eight-day observation. In the described case the early decontamination prevented the development of acute poisoning.

[Three-fold ethylene glycol poisoning over 3 years--a case report]. / Trzykrotne zatrucie glikolem etylenowym na przestrzeni 3 lat--opis przypadku.

This paper describes a case of now 49-year-old patient with alcohol dependence syndrome, hospitalized three times in the Center of Clinical Toxicology in 2009-2012 due to ethylene glycol poisoning. Twice, the course of poisoning was defined as severe. It was complicated by respiratory failure, severe metabolic acidosis, renal failure, disorders of the central nervous system; once referred to it as a medium, complicated by renal failure. He was treated with ethyl alcohol as an inhibitor of alcohol dehydrogenase, hemodialysess and intensive symptomatic and supportive therapy. This paper shows the great effectiveness of early hemodialysis and intensive therapy even in case of multiple and severe intoxication with toxic alcohols.

[Severe rhabdomyolysis syndrome in the course of alcohol withdrawal syndrome and hyponatremia]. / Ciezki zespól rabdomiolizy w przebiegu alkoholowego zespolu odstawienia i hiponatremii.

Rhabdomyolysis and associated kidney failure is a medical problem, often faced by doctors working in the centers of toxicology. Its most common cause is mechanical damage to the muscles, but predisposing factors include a big group of other pathologies and clinical conditions, including: electrolyte imbalance, immobility, infections, drug or psychoactive substances poisoning. The article presents an example of a patient with severe rhabdomyolysis syndrome caused by an alcohol withdrawal syndrome. Based on our experience and scientific studies of other clinical centres the paper presents various causes of muscle damage, including the iatrogenic effects of ethanol intoxication treatment. The article explains the importance of a proper and quick treatment which prevents damage of internal organs, including kidney failure.

[Tako-tsubo cardiomyopathy in the course of carbon monoxide poisoning]. / Kardiomiopatia tako-tsubo w przebiegu zatrucia tlenkiem wegla.

Tako-tsubo cardiomyopathy is a clinical syndrome induced by a strong mental or physical stress, characterized by a transient hypokinesia, akinesia or dyskinesia middle segments of the left ventricle and apical, with associated electrocardiographic changes of ST-T segment like in acute coronary syndrome, with no significant changes in coronary arteries in coronary angiography. Tako-tsubo cardiomyopathy is mainly found in women in the sixth and seventh decade of life and represents 1-2% of cases originally diagnosed as acute coronary syndrome. We present a case of tako-tsubo syndrome in the course of carbon monoxide poisoning in a 56-year-old patient, with a positive history of ischemic heart disease and hypertension. Moreover, the reasons for its occurrence were considered based on clinical course, laboratory tests and imaging, and available literature.

[Noncardiogenic pulmonary edema in the course of poisoning with clozapine, ketoprofen and thiethylperazine]. / Niekardiogenny obrzek pluc w przebiegu zatrucia klozapina, ketoprofenem i tietylperazyna.

Pulmonary edema is a severe, potentially fatal clinical condition. It happens, when interstitial fluid is accumulating in the alveoli, impeding proper gas exchange. Typically we distinguish cardiogenic and noncardiogenic pulmonary edema. The article describes the case of severe pulmonary edema, which occurred in a young woman, free of cardiac diseases, about 30 hours after a suicidal drug poisoning (clozapine, ketoprofen, thiethylperazine). Both clozapine and ketoprofen intoxication, may be severe. Complications in these poisonings affect not only the central nervous system, but also the circulatory or respiratory system and may even occur several hours after the overdose of these drugs. The study considered the causes and possible mechanisms of pulmonary edema in poisoning with these drugs.