rss_2.0General Interest FeedSciendo RSS Feed for General Interest Interest Feed Investigation of the Histology and Anatomy of Tobacco. 2nd Report / Mikroaufnahmen zur Histologie und Anatomie des Tabaks: II. Mitteilung Apparatus for the Measurement of the Pressure Drop of Cigarettes and Filter Rods / Automatisches Gerät zum Messen des Luftwiderstandes von Cigaretten und Filterstäben<abstract> <title style='display:none'>Abstract</title> <p> The prototype of an apparatus to measure the pressure drop of cigarettes is described. The apparatus works automatically at a speed of 400 cigarettes per hour. Results are indicated as number of cigarettes per draw resistance class of 5 mm WG</p> </abstract>ARTICLE2014-06-13T00:00:00.000+00:00The Distribution of the Air Flow through a Cigarette / Die Verteilung des Ventilationsstromes auf einer Cigarette<abstract> <p>The distribution of the air flow through the porous wrapping of a cigarette is</p> <p><disp-formula><inline-graphic xmlns:xlink="" xlink:href="graphic/Fig.1.png"/></disp-formula></p> <p>ν (λ, l) being the density of the air flow (cm<sup>3</sup> sec<sup>-1</sup> cm<sup>-1</sup>) on the paper wrapping at the position l if l is the length of the porous paper wrapping between the non-porous tip and the burning cone and l is the distance of the position in question from the non-porous tip. ν (λ, l) is given in air flow per cm rather than in air flow per cm<sup>2</sup> because of the cylindrical shape of the cigarette. I denotes the total stream at the mouth piece, a is the specific conductivity to air flow of the paper wrapping, b is the specific resistance to air flow of the tobacco rod, R<sub>G</sub> is the resistance to air flow of the burning cone [compare (1)]. The formula is derived and discussed. The dependence of the distribution of the ventilation stream on the length l and on the resistance RG is demonstrated for the case of a formerly investigated cigarette rod (1). The gradient of ν (λ, l) is</p> <p><disp-formula><inline-graphic xmlns:xlink="" xlink:href="graphic/Fig.2.png"/></disp-formula></p> <p>so that the density of the ventilation stream through the paper wrapping decreases almost linearly from its maximum at the tip to its minimum at the burning cone if the degree of ventilation is low, i.e. if the air flow I (λ, l) in the cigarette is not much higher at λ = 0 than at λ = l</p> </abstract>ARTICLE2014-06-13T00:00:00.000+00:00An Apparatus for the Determination of the Compactness of Cigarettes / Der Betriebs-Kompazitätsmesser<abstract> <title style='display:none'>Abstact</title> <p> An apparatus for the rapid determination of the compactness of cigarettes is presented. We may recall to mind that the compactness of a cigarette is the subjective measure of its filling regarded as average value of the whole of the cigarette. It does not take into account irregularities along the paper wrapping. The compactness thus applying to the total of cigarette filling has direct relation to the degree of exploitation of cut tobacco. In view of an optimum control of manufacture it is desirable to determine cigarette compactness by representative samples. The apparatus meets these requirements. It permits to measure the average compactness of a sample of 15 cigarettes in a short time and holds a device for the determination of tobacco humidity by which compactness values can be referred to a given standard of moisture. The apparatus is suitable for direct utilization in the factory</p> </abstract>ARTICLE2014-06-13T00:00:00.000+00:00Nicotine Degradation by Microorganisms in Model Experiments / Über Nikotinabbau durch Mikroorganismen in Modellversuchen<abstract xml:lang="de"> <title style='display:none'>Abstract</title> <p> Zur Verminderung des Nikotingehaltes stehen heute technologische Maßnahmen im Vordergrund. Eingangs wurde ein Überblick über die aus diesem Sektor vorliegenden Arbeiten über den mikrobiellen und biochemischen Nikotinabbau gegeben. An Hand von eingehenden Untersuchungen konnte gezeigt werden, daß spezielle Bakterien nach Zugabe von Vitamin- und Wuchsstoffen und bei guter Belüftung bis zu 70% der vorgelegten Nikotinmengen abzubauen imstande sind. Schimmelpilze zeigten sich ebenfalls zum Nikotinabbau befähigt. Die innerhalb der eigenen Versuche erhaltenen Abbaustufen wurden chromatographisch dargestellt. Diese bedürfen der weiteren chemischen und physiologischen Bestimmung. Die aus den eigenen mikrobiologischen Ergebnissen gezogenen Folgerungen wurden diskutiert und, soweit dies heute möglich ist, auf die Belange der praktischen Tabakfermentation, Tabakanalytik und Tabakzüchtung ausgerichtet</p> </abstract>ARTICLE2014-06-13T00:00:00.000+00:00Advancements and Challenges of Cigar Science, Testing and Regulation: A Review<abstract> <title style='display:none'>Summary</title> <p>On May 10, 2016, the U.S. Food and Drug Administration (FDA) published a Final Rule that extended its regulatory authority to all tobacco products, including e-cigarettes, cigars, hookah and pipe tobacco (Deemed Products). Effective August 8, 2016, this decision greatly expanded the scope of tobacco products being regulated by FDA and introduced significant testing challenges that need to be addressed. The major challenge for cigars in particular is testing as well as generation of accurate and reliable data, in the absence of certified reference products and standardized methodology for a product category with significant complexity and high inherent variability. In this article, we provide an overview of recent studies as well as active opportunities and on-going challenges associated with regulating and testing cigars. To the best of our knowledge, this is the first comprehensive review of non-clinical research for this product category (cigars). We are therefore convinced that, tobacco scientists and farmers, analytical chemists, cigar consumers, tobacco legal counsels, state and federal regulatory authorities will find this review beneficial and insightful.</p> </abstract>ARTICLE2022-08-15T00:00:00.000+00:00Editors’ Note Waterpipe is not a Cigarette, it is not Even a Conventional Pipe Susceptibility of Adult (Loew) (Diptera: Phoridae)<abstract> <title style='display:none'>Summary</title> <p><italic>Megaselia scalaris</italic> (Loew) (Diptera: Phoridae) is a synanthropic fly that lives in a wide range of warmer regions globally. Although it is listed as a quarantine pest in the Eurasian Economic Union, phytosanitary protocols have not been established. The larva feeds on moist food material and cannot grow on dry matter, including cured tobacco. However, adults of this species have been detected in containers containing tobacco in Russian ports. In this study, difference in susceptibility to phosphine between developmental stages and the lethal effect of phosphine on adults was evaluated. Fortunately, the adult which is the potential contaminable stage in tobacco was demonstrated to be the least tolerant. The phosphine concentrations to achieve probit 9 mortality (≈LC<sub>99.9968</sub>) for adult flies were calculated to be 636.2 ppm at 15 °C, 565.9 ppm at 20 °C, and 280.1 ppm at 25 °C with 6 h of exposure. The concentration × time products (<italic>Ct</italic>, ppm·d), the cumulative exposure to the fumigant, at respective temperatures were calculated as 159.1 ppm·d at 15 °C, 141.5 ppm·d at 20 °C, and 70.0 ppm·d at 25 °C, which are much lower than those recommended for the control of insect pests of cured tobacco leaves by CORESTA (Cooperation Centre for Scientific Research Relative to Tobacco). These are 1800 ppm·d (300 ppm × 6 d) at 16–20 °C and 800 ppm·d (200 ppm × 4 d) at temperatures higher than 20 °C. The results suggest that the standard fumigation protocol for stored tobacco will be adequate to control adult <italic>M. scalaris</italic>. The probit 9 values obtained in this study can be further utilized for the development of phosphine-based quarantine and preshipment treatments for this species.</p> </abstract>ARTICLE2022-08-15T00:00:00.000+00:00HPHC Testing of Tobacco and Smoke to Examine Cigarette Temporal Variability<abstract> <title style='display:none'>Summary</title> <p>Commercial cigarettes were analyzed for harmful and potentially harmful constituents (HPHCs) in tobacco and smoke to investigate temporal product variability independent of analytical variability over one week, one year, and three years. Cigarettes from the worldwide market with various design features were collected over a 3-year period, stored, and tested concurrently for HPHCs to minimize analytical variability; repeat testing of reference cigarette 3R4F was included as an analytical control for the study design. Physical parameters were found to be relatively consistent. No trends in variability were noted based on blend type, smoke analyte matrix, or magnitude of an HPHC's yield. Combustion-related HPHCs generally showed low variation. Long-term batch-to-batch variability was found to be higher than short-term variability for tobacco-related compounds that have the potential to vary over time due to weather and agronomic practices. “Tar”, nicotine, and carbon monoxide were tested in multiple labs and showed greater lab-to-lab variability than batch-to-batch variability across all phases. Based on the results of this study, commercial cigarette products appear to have relatively low product variability. The low analyte variability noted in this study with products tested under unconventionally controlled analytical conditions serves to indicate that analytical variability may be a significant contributor to overall variability for general product testing over time and in interlaboratory studies. Laboratory controls and using a matched reference product across studies and between laboratories are important to assess testing differences and variability.</p> </abstract>ARTICLE2022-08-15T00:00:00.000+00:00Investigation on the Lignin Removal From Tobacco Stem by a Solvothermal Method Using Ethylene Glycol as a Solvent<abstract> <title style='display:none'>Summary</title> <p>High lignin content of tobacco stem has been addressed as a drawback for its utilization on manufacture of reconstituted tobacco sheet. Therefore, the solvothermal method using ethylene glycol was investigated for the removal of lignin from tobacco stem. It was found that the removal efficiency of ethylene glycol on tobacco stem is much lower than that achieved on wheat straw and corncob, i.e., 13.9% <italic>vs</italic>. 39.3% and 44.1%, respectively. This can be rationalized in terms of the presence of solanesol in tobacco stem, which retards the strong hydrogen bond interaction between ethylene glycol and the free hydroxyl groups present in lignin. When solanesol was eliminated by applying an <italic>n</italic>-hexane extraction procedure, 40.5% of lignin was successfully dissolved from tobacco stem. The successful removal of lignin was further confirmed by the characterizing results of SEM, FT-IR and N<sub>2</sub>-sorption. The developed method provides a promising way to attenuate the negative effects of lignin on utilization of the otherwise wasted tobacco stem for production of reconstituted tobacco sheet.</p> </abstract>ARTICLE2022-08-15T00:00:00.000+00:00Integrated Pest Management Strategies for Cigarette Beetle Control in the Tobacco Industry – A Mini Review<abstract> <title style='display:none'>Summary</title> <p>The cigarette beetle (CB), <italic>Lasioderma serricorne</italic> (Cole-optera: Ptinidae), is a major insect pest to the tobacco industry worldwide. This insect is also a major pest of raw grains such as rough rice, and postharvest foods like certain high-value grain products like pet food, animal feed, breakfast cereals and various dried herbs and spices. Pest control methods and systematic integrated pest management (IPM) strategies are required for the CB in the tobacco industry to prevent economic damage to cured tobacco leaves in storages as well as finished products in retail and distribution chains. This paper presents an overview of the problem of CB infestation in the tobacco industry and describes and discusses strategies and IPM practices for managing the pest.</p> </abstract>ARTICLE2022-08-15T00:00:00.000+00:00Jānis Priedkalns – Outstanding Latvian Medical Scientist, 1934–2022 of the Difficult Laryngoscopy with Ultrasound Measurements of Hyomental Distance<abstract> <title style='display:none'>Abstract</title> <p>Ultrasound measurement of hyomental distance is promising as a predictor for difficult laryngoscopy in cases of difficult airway management. The aim of the study was to evaluate the prognostic value of ultrasound measurement of hyomental distance (HMD) for prediction of difficult laryngoscopy. Hyomental distance was sonographically measured in neutral (HMDn) and extreme head extension (HMDe) positions for fifty-six patients scheduled for elective surgery requiring tracheal intubation. Then the hyomental distance ratio (HMDR) was calculated. According to presence of difficult laryngoscopy assessed by the Cormack–Lehane (CL) score, patients were divided into a difficult laryngoscopy group (DL, n = 15) and easy laryngoscopy group (EL, n = 41). We calculated the sensitivity and specificity of HMDn, HMDe, and HMDR for difficult laryngoscopy. DL was present in 15 (27%) patients. We found a significant intergroup difference in HMDR between the DL and EL groups (1.12 ± 0.04 vs. 1.24 ± 0.06, respectively; p &lt; 0.001). In contrast, we were not able to find a significant difference for HMDn and HMDr. HMDR had the highest sensitivity 86.7% and specificity 85.4% (p &lt; 0.01) to predict difficult laryngoscopy, where the area under the curve was 0.939; p &lt; 0.01 for HDMR &lt; 1.2 cm. Moreover, we found that difficult laryngoscopy was associated with higher body mass index (BMI), with higher values in the DL group compared to EL patients (34.3 ± 9.1 vs. 28.5 ± 5.7 kg/m<sup>2</sup>, respectively; p = 0.035). HMDR &lt; 1.2 cm measured by ultrasound might have a good predictive value for prediction of difficult laryngoscopy.</p> </abstract>ARTICLE2022-07-23T00:00:00.000+00:00Transcranial Duplex Ultrasonography Measurements Towards Identification of Blood Vessel Conditions: Artificial Cerebral Blood Flow in Pathologies<abstract> <title style='display:none'>Abstract</title> <p>The aim of the study was to investigate how cerebral vasospasm, vasodilation and haemorrhage under artificial circulation conditions during cardiopulmonary bypass affect transcranial duplex ultrasonography measurements. A description of transcranial duplex ultrasonography and phantom development is provided. Measurements were made using a commercially available ultrasound system and cardiopulmonary bypass machine, water phantom and 32% glycerol solution with cornstarch. The experiments showed that the cerebral blood vessel condition in artificial circulation affects transcranial duplex ultrasonography measurement limit values. The most sensitive parameter for blood vessel condition changes is Peak Systolic Velocity (PSV) for which changes were observed in 100% of cases. The most insensitive was Time-Averaged Peak-Velocity (TAPV), and Minimum Diastolic Velocity (MDV) for which changes were observed in 83% of cases.</p> </abstract>ARTICLE2022-07-23T00:00:00.000+00:00Effect of a Modified AN69ST Membrane on the Clinical Course of Adult Patients with Bacterial Septic Shock<abstract> <title style='display:none'>Abstract</title> <p>Sepsis is among the leading causes of mortality globally. Blood purification techniques are evolving in sepsis therapy, aiming at pathogenic antigens and host cytokines. The aim of this study was to determine whether continuous renal replacement therapy (CRRT) with modified AN69ST membrane, brand name oXiris, improves the clinical course of adult patients with septic shock. The study had a retrospective, longitudinal, propensity score matching (PSM) design with two groups: treatment — CRRT started with oXiris, control — used ST150 filters only. Data from 636 patients were analysed. The oXiris and control groups included 40 and 57 patients, respectively. PSM left 19 patients in each group. Ten of 19 patients died in the oXiris group. Survival, CRRT duration, intensive care unit or hospital length of stay did not differ between the groups. The oX-iris group had a tendency for lower mortality in Gram-negative infection cases, though not statistically significant. During the first 72h of CRRT, both groups had improvement in noradrenaline requirement, arterial pressure and blood lactate. However, with oXiris treatment, increase of arterial pressure (TA) was greater during CRRT during the first 24h and there was a more significant decrease of noradrenaline infusion and lactate during the first 72 h. We concluded that in septic shock early CRRT with oXiris may be beneficial and that there might be decreased hospital mortality in the case of Gram-negative infection. Further larger studies are required.</p> </abstract>ARTICLE2022-07-23T00:00:00.000+00:00Assessment of Anaesthesia Nurses’ Attitude to Teamwork<abstract> <title style='display:none'>Abstract</title> <p>Teamwork is one of the most important aspects in medicine today. It is known that the operating room is the place where communication is most needed between doctors and other medical staff. The purpose of this study was to analyse the view of nurses towards collaboration between the physician and nurse in an anaesthesiology department depending on education and work experience. The study was conducted in three Lithuanian hospitals. The questionnaires “Jefferson scale of attitudes toward physician–nurse collaboration” and “Barriers of communication between doctors and nurses” were used. The statements of the questionnaires were rated using the Likert scale; the attitude was evaluated as positive when the assessment was more than median (2.5). The results were processed by SPSS Statistics 23.0 pack, using descriptive statistics and ANOVA, with statistically significant results when p &lt; 0.05. A total of 138 nurses participated in this study, all female, aged 43.00 ± 12.48 years and with different education levels. According to the nurses, the most important aspects of teamwork were dominance of physicians (3.08 ± 0.65), nurse’s autonomy (3.46 ± 0.54), patient care (3.33 ± 0.56) and sharing knowledge and cooperation (3.33 ± 0.47) (F = 12.47; p &lt; 0.001). Patient care and autonomy of nurses were most important aspects for nurses with higher education and short job experience, and physician dominance was the most important for nurses with a longer job experience and lower education level. Barriers to cooperation arising from environmental factors are the greatest drivers for ineffective teamwork.</p> </abstract>ARTICLE2022-07-23T00:00:00.000+00:00Clinical Characteristics of Invasively Ventilated Covid-19 Patients: An Overview of Clinical Experience in Pauls Stradiņš Clinical University Hospital, Rīga, Latvia<abstract> <title style='display:none'>Abstract</title> <p>This retrospective single-centre study was conducted in an intensive care unit (ICU) in Pauls Stradiņš Clinical University Hospital (Rīga, Latvia) between 1 October 2020 and 30 April 2021. The aim was to assess the baseline clinical characteristics and their association with outcome for critically ill coronavirus disease 2019 (COVID-19) patients admitted to the ICU and requiring invasive mechanical ventilation (IMV). Demographic, clinical, laboratory, length-of-stay and mortality data were collected from medical records. In total, 66 critically ill patients admitted to the ICU were enrolled in this study. 77% were male, and the median age was 65.5 [57.0–70.8] years. Comorbidi-ties included obesity (67.2%), cardiovascular disease (63.6%) and type II diabetes (38.1%). Prone positioning was performed in most cases (68.2%) and one-third (34.8%) of patients required renal replacement therapy during their stay in the ICU. The median time to intubation after hospitalisation was eight [3.3–10.0] days. The median length-of-stay in the ICU was 12 [6.0–18.5] days and the overall mortality among all invasively ventilated patients in the ICU was 86%. In survivors, the duration of time between the onset of symptoms and hospitalisation, and time between the onset of symptoms and intubation, were found to be shorter than in non-survivors.</p> </abstract>ARTICLE2022-07-23T00:00:00.000+00:00Causes of Suboptimal Preoxygenation Before Tracheal Intubation in Elective and Emergency Abdominal Surgery<abstract> <title style='display:none'>Abstract</title> <p>Optimal preoxygenation (PO) prior to tracheal intubation reduces the risk of arterial desaturation and prolongs the period of safe apnoea. The common methods of PO are mask ventilation with 100% O<sub>2</sub> for 3–5 minutes or, alternatively, asking the patient to take eight deep breaths in a minute. Our study group conducted a prospective study to assess the impact of the most common risk factors on PO and to compare the efficiency of PO in patients undergoing elective and emergency abdominal surgery without premedication. PO was performed using mask ventilation with 6 l/min of 100% oxygen for 5 minutes. End-tidal oxygen (EtO<sub>2</sub>) was documented in 30-second increments. We found that optimal PO (EtO<sub>2</sub> &gt; 90%) was not achieved by almost half of the patients (46%) and that this was more common in the elective surgery group. Effective PO was not impacted by any of the evaluated risk factors for suboptimal oxygenation. Despite these findings, we believe that the identification of potential risk factors is crucial in the pre-anaesthesia stage, given the benefits of optimal PO.</p> </abstract>ARTICLE2022-07-23T00:00:00.000+00:00Changes in Cerebral Oximetry in Patients Undergoing Shoulder Replacement Surgery<abstract> <title style='display:none'>Abstract</title> <p>Degenerative joint diseases affect the elderly population, and advanced orthopaedic surgery offers novel solutions. The semi-sitting position is used during shoulder replacement surgery. There have been reports of transient and permanent neurological damage following surgery. We aimed to determine cerebral desaturation events (CDEs) during shoulder replacement surgery under general anaesthesia. This prospective, observational study was conducted at the Hospital of Traumatology and Orthopaedics. A cohort of 24 patients received combined plexus brachialis block and endotracheal anaesthesia. Their cerebral regional oxygen saturation index (rSO<sub>2</sub>) and mean arterial blood pressure (MAP) were recorded and compared in predefined intervals: before induction, post-induction, after getting in a sitting position, after cementing, and after extubation. Hypotension was defined as the occurrence of any of the following: either a &gt; 30% decline in MAP from the baseline or a MAP &lt; 65 mmHg. CDEs were defined as a 20% reduction in frontal lobe oxygenation. Calculations were made using SPSS software (Version 14.0.2, SPSS Inc.). There was a significant correlation between MAP and rSO<sub>2</sub> after positioning, between MAP after intubation and rSO<sub>2.</sub>, and between MAP before intubation and rSO<sub>2</sub> at the end of surgery. One in three patients who experienced hypotension also experienced a CDE. rSO<sub>2</sub> fluctuations correlated with MAP.</p> </abstract>ARTICLE2022-07-23T00:00:00.000+00:00en-us-1