29 research outputs found
A Natural Deep Eutectic Solvent - Protonated L-Proline-Xylitol - Based Stationary Phase for Gas Chromatography
The paper presents a new kind of stationary phase for gas chromatography based on deep eutectic solvents (DES) in the form of a mixture of L-proline (protonated with hydrochloric acid) as a hydrogen bond acceptor (HBA) and xylitol as a hydrogen bond donor (HBD) in a molar ratio of HBA:HBD 5:1. DES immobilized on a silanized chromatographic support was tested by gas chromatography (GC) in order to determine its resolving power for volatile organic compounds. Studies have demonstrated the suitability of this type of DES as a stationary phase for GC. The Rohrschneider-McReynolds constants were determined for the synthesized DES, revealing that it is a polar stationary phase (Σ(ΔI) = 1717). The selectivity of DES is influenced by the presence of hydroxyl groups in the xylitol structure capable of forming hydrogen bonds of a donor nature and the proton acceptor properties of the protonated L-proline structure. The presence of additional interactions is brought about by the presence of the carboxyl group. As a result, the retention of alcohols is several times higher (200-670%) than the expected value based on their boiling points. A significant increase in retention (400-970%) was also found for pyridine derivatives. The developed DES stationary phase is characterized by very good repeatability of retention and stability (up to 140°C). The efficiency of the prepared columns (6300-11300 theoretical plates/m) and the selectivity of the DES stationary phase are competitive with the commercial products
New Simple and Robust Method for Determination of Polarity of Deep Eutectic Solvents (DESs) by Means of Contact Angle Measurement
The paper presents a new method for evaluating the polarity and hydrophobicity of deep eutectic solvents (DESs) based on the measurement of the DES contact angle on glass. DESs consisting of benzoic acid derivatives and quaternary ammonium chlorides–tetrabutylammonium chloride (TBAC) and benzyldimethylhexadecylammonium chloride (16-BAC)—in selected molar ratios were chosen for the study. To investigate the DESs polarity, an optical goniometer and an ET(30) role= presentation style= box-sizing: border-box; max-height: none; display: inline; line-height: normal; font-size: 13.2px; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(34, 34, 34); font-family: Arial, Arial, Helvetica, sans-serif; position: relative; \u3eET(30)��(30) solvatochromic scale based on Reichardt’s dye were used. The research demonstrated the high accuracy and precision of the developed procedure. The simplicity of the examination and the availability of basic equipment allow for the implementation of the developed method in routine investigations of DESs
Lymphoedema — assessment of the diagnostic and prognostic value of upper arm dynamic lymphoscintigraphy in patients after mastectomy
Obrzęk limfatyczny po operacyjnym leczeniu raka piersi z usunięciem węzłów chłonnych pachowych często
utrudnia powrót do prawidłowej aktywności z powodu zwiększenia objętości kończyny, zniekształcenia,
ograniczenia ruchomości w stawach i przykurczów mięśniowych. Celem pracy była ocena korelacji między
dynamiką przepływu chłonki w obrębie kończyn górnych u pacjentek po leczeniu operacyjnym raka piersi
a skutecznością leczenia obrzęku limfatycznego. Badaniami objęto 20 kobiet. Badania wykonano za pomocą
g-kamery Varicam, firmy ELSCINT po podskórnym podaniu 0,5 ml Nanocollu znakowanego 1 mCi 99mTc.
Stopień niewydolności układu chłonnego określano na podstawie 4-stopniowej skali Weissledera, z wykreśleniem
krzywej narastania aktywności w badanej grupie węzłów chłonnych. Na podstawie wykonanych
badań stwierdzono, że większy stopień redukcji obrzęku mierzony procentowym ubytkiem objętości wyjściowej
korelował z mniejszym stopniem niewydolności chłonnej określonej na podstawie limfoscyntygrafii
dynamicznej (p < 0,05). Limfoscyntygrafia dynamiczna w połączeniu ze statyczną pozwala więc ustalić nie
tylko stopień niewydolności układu chłonnego, ale również określić rodzaj i przewidywaną skuteczność
terapii.Upper arm lymphoedema is a very debilitating consequence of breast cancer therapy because of excessive
limb volume, shape distortion, mobility limitation. The aim of the research was to assess the correlation
between lymph outflow impairment and complex decongestive therapy (CDT) effectiveness in breast cancer
related lymphoedema. There were 20 women included into the procedure. Lymphoscintigraphy (LAS) was
made on g-camera Varicam (ELSCINT) after subcutaneous injection of 0.5 ml Nanocoll labeled 99mTc (1 mCi).
Lymphatic insufficiency was defined on the basis of four-step Weissleder scale. The results showed that the
higher the level of lymphatic insufficiency the worse effects were achieved during CDT (p < 0.05). Dynamic
LAS combined with the static one have a good predictive value of CDT effects
What Should Be the Topics of a Prospective Study on Ovarian Masses in Children?—Results of a Multicenter Retrospective Study and a Scoping Literature Review
Purpose: to determine management problems of ovarian masses in girls in order to form a baseline for prospective randomized studies of the established topics and quality improvement of our management. Materials and Methods: We performed a national analysis of clinical aspects of ovarian masses in girls operated on in Poland, analyzed retrospectively medical files of all consecutive patients aged 0–18 who underwent surgeries for ovarian lesions between 2012 and 2017 at 17 pediatric surgical departments and complemented the analysis with a scoping review of a recent primary research related to ovarian masses in children. Results: The study group comprised 595 patients. Forty-four (7.39%) girls were diagnosed with malignant tumors. The overall preservation rate was 64.54%. The analysis revealed that positive tumor markers (OR = 10.3), lesions larger than 6 cm (OR = 4.17) and solid mass on ultrasound examination (OR = 5.34) are interdependent variables differentiating malignant tumors from non-malignant lesions (X42 = 79.1; p = 0.00000). Our scoping review revealed 10 major branches of research within the topic of ovarian masses in pediatric population. Conclusions: We have developed an overview of the field with the emphasis on the local environment. Our next step is a multi-institutional prospective study of a quality improvement project implementation based on the obtained knowledge
Ovarian teratoma in children: a plea for collaborative clinical study
Abstract Background Although teratomas are the most common histologic subtype of childhood ovarian germ cell tumors, their appropriate treatment in this age group still remains unclear. Paucity of research dedicated exclusively to both mature and immature teratomas of the ovary, contribute to decision making difficulties. Therefore, we decided to review retrospectively our experience in treatment of pediatric ovarian teratomas in order to assess the epidemiology, presenting features, and diagnostic as well as surgical management of these lesions. Results The study comprised 58 patients. Fifty percent of patients were between 9 and 15 years old. Mature teratoma was diagnosed in 55(94.83%) patients, while 3(5.17%) patients presented with immature teratoma. Twenty eight (50.91%) girls with mature teratoma had laparotomy and 23 (41.82%) had laparoscopy performed as an initial operative approach. Ovarian tissue sparing technique (preservation of the ovarian tissue of the affected gonad) was applied in only 11.11% of patients operated in the first study period (years 1999–2003) and increased to 40.54% in the second half of our study (years 2004–2016). The extent of gonadal resection was not related with the size of the lesion. Bilateral lesions were noted in 8 patients with mature teratoma. All girls with immature teratoma were subjected to formal laparotomy. Two patients had stage III of the disease and one had stage IV. They underwent at least resection of the affected gonad. Adjuvant chemotherapy was given to all girls with immature teratoma after the surgery. Conclusions Under particular conditions ovarian-sparing surgery might be successfully applied in children with mature teratoma. Laparotomy is the treatment of choice in large masses, suspicious for malignancy and if surgical staging is required. High quality prospective multi-institutional studies are required in order to get an objective insight into biology and prognostic factors of teratomas in children
Selecting treatment method for ovarian masses in children – 24 years of experience
Abstract Background Epidemiology and pathology of ovarian tumors in the pediatric population are very different of these encountered in women. Few attempts have been made to analyze the whole spectrum of ovarian pathology in children, and only some of them included series of more than 200 cases. We performed a retrospective analysis of clinical and diagnostic aspects of ovarian tumors and tumor-like lesions in girls in order to identify the characteristics associated with malignancy with an attempt to elaborate a clinical management algorithm. Results The study group comprised 214 patients operated on for ovarian tumor in years 1991-2014 at the pediatric surgical center. Non-neoplastic ovarian lesion was diagnosed in 127 females. Sixty-five patients had a benign tumor and 22 had a malignant lesion. Abdominal pain was the most common symptom in the non-malignant lesion group. Patients with ovarian malignancy presented predominantly with abdominal distension and palpable mass. In the non-malignant group imaging studies revealed cystic lesion in 124 patients (68.89%) and solid mass in 10 (5.55%). Malignant lesion showed a solid or mixed structure in all cases. Positive tumor markers were noted in 14 (13.7%) patients with a benign lesion and in 14 (70%) with ovarian malignancy. Large lesions were found in 77.3% of girls with a malignant mass, while only in 32.8% of patients with a benign lesion (p < 0.001). In the group of solid tumors positive tumor marker results occurred more frequently in patients with diagnosed malignant tumors (p < 0.05). Positive tumor markers, large size of the lesion and age below 14 years were independent variables differentiating malignant tumors from non-malignant lesions (p = 0.00000). Conclusions Predominantly solid structures noted on imaging studies, large dimension and positive tumor markers are clinical predictors of malignancy. A diagnosis of purely cystic lesions with negative markers or of a small size should be an indication for a gonad-sparing procedure. Treatment guidelines for ovarian lesions in children should be established on the basis of multicenter prospective studies and introduced as soon as possible in order to improve and unify the ovarian preservation rates across the pediatric surgical centers
Role of Fungi in Biodegradation of Imidazolium Ionic Liquids by Activated Sewage Sludge
Ionic liquids (ILs), due to their specific properties, can play the role of persistent water contaminants. Fungi manifest the ability to decompose hardy degradable compounds, showing potential in the biodegradation of ILs, which has been studied extensively on sewage sludge; however, attention was drawn mainly to bacterial and not fungal species. The aim of the research was to determine the significance of fungi in ILs’ biodegradation to extend the knowledge and possibly point out ways of increasing their role in this process. The research included: the isolation and genetic identification of fungal strains potentially capable of [OMIM][Cl], [BMIM][Cl], [OMIM][Tf2N], and [BMIM][Tf2N] degradation, adjustment of the ILs concentration for biodegradability test by MICs determination and choosing strains with the highest biological robustness; inoculum adaptation tests, and finally primary biodegradation by OECD 301F test. The study, conducted for 2 mM [OMIM][Cl] as a tested substance and consortium of microorganisms as inoculum, resulted in an average 64.93% biodegradation rate within a 28-day testing period. For the individual fungal strain (Candida tropicalis), the maximum of only 4.89% biodegradation rate was reached in 10 days, then inhibited. Insight into the role of fungi in the biodegradation of ILs was obtained, enabling the creation of a complex overview of ILs toxicity and the possibilities of its biological use. However, only an inoculum consisting of a consortium of microorganisms enriched with a selected strain of fungi was able to decompose the IL, in contrast to that consisting only of an individual fungal strain
First Deep Eutectic Solvent-Based (DES) Stationary Phase for Gas Chromatography and Future Perspectives for DES Application in Separation Techniques
The paper presents the first application of deep eutectic solvents (DES) as stationary phases for gas chromatography. DES obtained by mixing tetrabutylammonium chloride (TBAC) as a hydrogen bond acceptor (HBA) with heptadecanoic acid being a hydrogen bond donor (HBD) in a mole ratio of HBA:HBD equal to 1:2 was characterized by its ability to separate volatile organic compounds (VOCs). The Rohrschneider – McReynolds constants determined reveal that the synthesized DES is a stationary phase of medium polarity. A detailed retention characteristic was determined for a number of groups of chemical compounds, including aromatic hydrocarbons, alcohols, ketones, sulfides and thiophene derivatives. The synthesized DES was found to have a high selectivity towards alcohols. At the same time, the investigated stationary phase was found to have specific interactions with some analytes. For example, a stronger retention was observed for 1-hexanol and 1-heptanol compared to other alcohols. Retention times of these two alcohols are longer by 191% and 300%, respectively, relative to the expected value based on their boiling point. Such an increased retention is caused by a synergistic effect of various kinds of interactions – the possibility of formation of hydrogen bonds between the DES and the hydroxyl group of alcohols and hydrophobic interactions of alkyl chains of the DES with the alkyl chain of alcohols. The ability to modify properties of DESs by replacement of HBA or HBD with a different chemical compound or by dissolving in DES macromolecular substances makes the proposed stationary phase highly flexible. In addition to using the developed DES in chromatographic techniques, the retention data collected indicate the possibility of its application to other separation techniques, i.e. extractive distillation
A Novel Type of Stationary Phase for Gas Chromatography Based on Protonated L-Proline-Xylitol Deep Eutectic Solvent (Des)
The paper presents a new kind of stationary phase for gas chromatography based on deep eutectic solvents (DES) in the form of a mixture of L-proline (protonated with hydrochloric acid) as a hydrogen bond acceptor (HBA) and xylitol as a hydrogen bond donor (HBD) in a molar ratio of HBA:HBD 5:1. DES immobilized on a silanized chromatographic support was tested by gas chromatography (GC) in order to determine its resolving power for volatile organic compounds. Studies have shown that this type of DES has very good properties as a stationary phase for GC. Determined Rohrschneider-McReynolds constants reveal that the synthesized DES is a polar stationary phase. The selectivity of DES is influenced by the presence of hydroxyl groups in the xylitol structure capable of forming hydrogen bonds of a donor nature and the proton acceptor properties of the protonated L-proline structure. The presence of additional interactions is brought about by the presence of the carboxyl group. As a result, the retention of alcohols is several times higher than the expected value based on their boiling points. A significant increase in retention was also found for pyridine derivatives. The developed DES stationary phase is characterized by very good repeatability of retention and stability. The efficiency of the prepared columns and the selectivity of the DES stationary phase are competitive with the commercially available products