Examination of a Structural Preference in Quaternary Alkali-Metal (A) Rare-Earth (R) Copper Tellurides by Combining Experimental and Quantum-chemical Means.

In the quest for materials addressing the grand challenges of the future, there is a critical need for a broad understanding of their electronic structures because the knowledge of the electronic structure of a given solid allows us to recognize its structural preferences and to rationalize its properties. As previous research on quaternary chalcogenides containing active metals (a group-I- or -II-element), early transition-metals, and late transition-metals indicated that such materials could pose as alluring systems in the developments of thermoelectrics, our impetus was stimulated to probe the suitability of tellurides belonging to the prolific A3R4Cu5Te10-family. In doing so, we first used quantum-chemical techniques to explore the electronic and vibrational properties of representatives crystallizing with different A3R4Cu5Te10 structure types. The outcome of these explorations indicated that the aspects that control the formation of a given type of A3R4Cu5Te10 structure are rather subtle so that transitions between different types of A3R4Cu5Te10 structures could be induced by manipulating the ambient conditions. To probe this prediction, we explored the thermal behavior for the example of one quaternary telluride, that is, Rb3Er4Cu5Te10, and thereby identified a new type of A3R4Cu5Te10 structure. Because understanding the structural features of the A3R4Cu5Te10 family plays an important role in the analyses of the aforementioned explorations, we also present an overview about the structural features and the members of this class of quaternary tellurides. In this connection, we also provide a structural report of four tellurides, that is, K3Tb4Cu5Te10 and Rb3R4Cu5Te10 (R = Tb, Dy, Ho), which have been obtained from high-temperature solid-state reactions for the very first time.

Long-term audiological benefit with an active transcutaneous bone-conduction device: a retrospective cohort analysis.

PURPOSE: To evaluate long-term audiological, surgical and safety outcomes of a complex patient cohort treated with an active transcutaneous bone-conduction device (tBCD). METHODS: This retrospective, monocentric cohort analysis involves 31 adults with conductive (CHL) and mixed hearing loss (MHL). For outcome analysis, study results were divided into short-term follow-up data (< 12 months) and long-term follow-up data (> 12 months). RESULTS: 31 patients with a total person-time of 90.4 years and an average number of 3.2 ± 1.5 preoperatively performed surgeries on the implanted side were investigated. Mean BCD-aided PTA4 thresholds were significantly lower than unaided PTA4AC before surgery (64.7 ± 16.1 dB HL; CHL 50.6 ± 10.6 dB HL; MHL 72.8 ± 12.8 dB HL) and did not change between short-term (42.3 ± 13.1 dB HL; CHL 35.8 ± 6.8 dB HL; MHL 45.2 ± 14.3 dB HL) and long-term (43.4 ± 10.0 dB HL; CHL 35.8 ± 4.3 dB HL; MHL 48.1 ± 9.6 dB HL) follow-up periods. Speech intelligibility in the Freiburg monosyllables test at 65 dB improved significantly, from 16.3 ± 21.5% (CHL 26.8 ± 19.0%; MHL 8.7 ± 20.5%) in the unaided condition to 82.7 ± 15.5% (CHL 90.0 ± 12.2%; MHL 79.4 ± 16.3%) in the short-term and 85.5 ± 13.2% (CHL 93.8 ± 7.9%; MHL 79.5 ± 13.3%) BCD-aided in the long-term follow-up periods. Ten minor procedure-related and 6 implant-related (5 minor, 1 major) AEs occurred over the total follow-up period. CONCLUSION: The device provides satisfactory audiological and speech benefit over long-term follow-up periods, up to 7 years. Explant rates were very low, while the overall rate of manageable AEs was high in this complex patient cohort. The device is considered a safe and effective option in the long-term hearing rehabilitation of patients with CHL and MHL.

[Emergencies in ear, nose and throat medicine]. / Notfälle in der Hals-, Nasen- und Ohrenheilkunde.

Emergencies in ear, nose and throat medicine in the preclinical setting are common. Due to the narrow anatomical conditions, relocation or bleeding in this area can quickly lead to an emergency situation. In this article, the most important causes of bleeding, shortness of breath and trauma are to be presented and the corresponding treatment briefly outlined.

Daiquiri: a web-based user interface framework for beamline control and data acquisition.

Daiquiri is a web-based user interface (UI) framework for control system monitoring and data acquisition designed for synchrotron beamlines. It provides simple, intuitive and responsive interfaces to control and monitor hardware, launch acquisition sequences and manage associated metadata. Daiquiri concerns itself only with the UI layer; it does not provide a scan engine or controls system but can be easily integrated with existing systems.

Antimicrobial resistance of Helicobacter pylori in an eastern German region.

BACKGROUND: Antimicrobial therapy is recommended to eradicate Helicobacter (H.) pylori in infected individuals. As first-line treatments are empiric, knowledge of antimicrobial resistance is key to successful eradication. AIMS: We investigated primary resistance in an eastern German region to derive recommendations for eradication treatment. METHODS: We used molecular genetic methods to examine Helicobacter rapid urease test (RUT) positive gastric specimens of 533 patients from Berlin and the federal state of Brandenburg with allegedly no prior eradication treatment. Tissue samples were removed from RUT and screened by real-time PCR for mutations conferring resistance to clarithromycin. In addition, 182 samples out of 533 were tested for resistance to levofloxacin and tetracycline. RESULTS: Primary resistances were 10.9% (58 out of 533) to clarithromycin; 13.7% (25/182) to levofloxacin; and 2.2% to tetracycline (4/182). Combined resistance to clarithromycin/levofloxacin was low (2.2%, 4/182). Female sex was significantly associated with clarithromycin resistance. CONCLUSION: Clarithromycin may be a suitable first-line antibiotic for about 90% of outpatients. A simple molecular test may help physicians avoid prescription of an ineffective first-line regimen.

Acceptance and adoption of transoral robotic surgery in Germany.

PURPOSE: Since its introduction over a decade ago, the use of robotic surgery (RS) in head and neck surgery has widely spread around the globe, with very differential adoption of this novel surgical technique in different parts of the world. In this study, we analyze the acceptance and adoption of robotic surgery in the head and neck in Germany. MATERIALS AND METHODS: A cross-sectional analysis using a questionnaire evaluating the acceptance and adoption of RS was performed. Questionnaires were distributed to all chairmen /-women of Otorhinolaryngology, Head and Neck Surgery Departments in Germany. RESULTS: A total of 107 respondents completed the questionnaire (65.2%). At university hospitals, 71.4% of the respondents indicated that a robotic system was available, and 21.4% responded that robotic surgery was performed at their institution; 22.7% and 0.04%, respectively, at non-university hospitals. The overall adoption rate was 0.8%. The most common cases performed were TORS resection in the oropharynx. Main reasons for not adopting this technique were costs, lack of interest and available co-operations. CONCLUSION: This study provides evidence of the extent of adoption of TORS in Germany; main perceived barriers to adoption are costs with lack of cost-covering reimbursement and insufficient co-operations with other disciplines as well as hospital administration resulting in a very low adoption rate of this technique over the past decade. Results from this study may assist in decision-making processes on adopting this technique in the future.

From yellow to silver: Transforming cranial morphology in European eel (Anguilla anguilla).

The European eel (Anguilla anguilla) has been extensively studied, especially because of its highly specialized migratory behaviour associated with substantial phenotypic transformations. During this migration, one of those transformations the eel undergoes is from yellow to silver eel, a process known as silvering. Although the cranial morphology during the earlier glass, elver and yellow eel stages are well studied, little is known about actual morphological changes during the transformation process from the yellow to the silver eel stage. Yet, literature suggests drastic changes in musculoskeletal anatomy. Here, we investigated the cranial musculoskeletal morphology of 11 male European eels at different stages during silvering, resulting both from natural and artificial maturation. Using 3D-reconstructed µCT data of the head, the skull and cranial muscles associated with jaw closing and respiration were studied. Eye size was used as a proxy for the silvering stage. Size-adjusted jaw muscle volumes increased during silvering, although insignificantly. Accordingly, a near-significant increase in bite force was observed. Respiratory muscles size did increase significantly during silvering, however. Considering the eel's long migration, which often includes deep and thus potentially oxygen-poor environments, having a better performing respiratory system may facilitate efficient migration. Both overall skull dimensions and specifically orbit size increased with eye index, suggesting they play a role in accommodating the enlarging eyes during silvering. Finally, artificially matured eels had a wider and taller skull, as well as larger jaw muscles than wild silver eels. This could be caused (a) by different conditions experienced during the yellow eel stage, which are maintained in the silver eel stage, (b) by side effects of hormonal injections or (c) be part of the maturation process as artificially induced silver eels had a higher eye index than the wild silver eels.

Etiology and therapy of delayed facial paralysis after middle ear surgery.

PURPOSE: This review focuses on the etiology, incidence and therapy of delayed paralysis of the facial nerve (DFP) after different types of middle ear surgery. METHODS: Retrospective review of studies published in English from 1970 until 2019 reporting DFP after tympanoplasty, tympanomastoid surgery, stapedotomy and stapedectomy. The search used the databases of PubMed, Scopus and Cochrane Library. Studies reporting from adult patients and DFP onset after 48 h after surgery were included. Studies dealing with iatrogenic or preexisting facial palsy and case reports were excluded. The initial literature search resulted in 52 studies. The relevance of the publications was verified using title, abstract and full-text analysis. Data were analyzed with descriptive statistics using median, simple sum and statistical significance. RESULTS: Ten studies having 12,161 patients could be included in this review. The incidence of DFP after the middle ear surgeries varies between 0.2 and 1.9%. The surgical stress of the middle ear surgeries is the main trigger for the development of DFP and leads to a virus reactivation and/or neuronal edema. Patients with a dehiscence of the facial canal have a significantly higher probability for a DFP. The recommended therapy of DFP based on the data of the therapy of Bell's palsy, consists of the administration of a steroid. For patients having a case history of previous viral infections, an antiviral prophylaxis is recommended. CONCLUSION: Overall, DFP has a very good prognosis, with mostly complete healing with appropriate therapy. Viral reactivation is the most favored genesis of DFP. Immunization or antiviral prophylaxis is recommended to those patients being at risk for a viral reactivation.

Burrowing behaviour of the European eel (Anguilla anguilla): Effects of life stage.

The European eel (Anguilla anguilla) is a fascinating species, exhibiting a complex life cycle. The species is, however, listed as critically endangered on the IUCN Red List due to an amalgam of factors, including habitat loss. This study investigated the burrowing behaviour and substrate preference of glass, elver and yellow stages of A. anguilla. Preference was determined by introducing eels in aquaria with different substrates and evaluating the chosen substrate for burrowing. In addition, burrowing was recorded using a camera in all substrate types and analysed for kinematics. The experiments showed that all of these life stages sought refuge in the sediments with particle sizes ranging from sand to coarse gravel. Starting from a resting position, they shook their head horizontally in combination with rapid body undulations until half of their body was within the substrate. High-speed X-ray videography revealed that once partly in the sediment, eels used only horizontal head sweeps to penetrate further, without the use of their tail. Of the substrates tested, burrowing performance was highest in fine gravel (diameter 1-2 mm; lower burrowing duration, less body movements and/or lower frequency of movements), and all eels readily selected this substrate for burrowing. However, glass eels and elvers were able to use coarse gravel (diameter >8 mm) because their smaller size allowed manoeuvring through the spaces between the grains. Further, burrowing performance increased with body size: glass eels required more body undulations compared to yellow eels. Interestingly, the urge to hide within the sediment was highest for glass eels and elvers. Documentation of substrate preference and burrowing behaviour of A. anguilla provides new information about their potential habitat use. Considering that habitat alterations and deteriorations are partly responsible for the decline of the eel, this information can contribute to the development of more effective conservation measures.

Homo- and Heteroleptic Coordination Polymers and Oxido Clusters of Bismuth(III) Vinylsulfonates.

The synthesis and characterization of six homo- and heteroleptic coordination polymers and oxido clusters of bismuth(III) vinylsulfonates are reported. The solvent-mediated reaction of BiPh3 and vinylsulfonic acid in ethanol produces [{Ph2 Bi(O3 SCH=CH2 )}n ] (1), which crystallizes as a one-dimensional coordination polymer as a result of bridging sulfonato ligands accompanied by intermolecular Bi⋅⋅⋅ π(arene) London dispersion interactions. In solution, compound 1 equilibrates to give [{PhBi(O3 SCH=CH2 )2 }n ] (2) and BiPh3 . Compound 2 is obtained as a single product by the reaction of BiPh3 with vinylsulfonic acid in acetonitrile and crystallizes as a one-dimensional coordination polymer. The homoleptic vinylsulfonate [{Bi(O3 SCH=CH2 )3 }n ] (3) was isolated as a two-dimensional coordination polymer, which is quite moisture sensitive, but did not provide a distinct polynuclear bismuth oxido cluster upon hydrolysis. However, by treatment of [Bi6 O4 (OH)4 (NO3 )6 ]⋅H2 O or [Bi38 O45 (OMc)24 (dmso)9 (H2 O)2 ]⋅2 DMSO⋅5 H2 O (OMc=methacrylate) with vinylsulfonic acid, such a cluster, namely, [Bi9 O7 (OH)(O3 SCH=CH2 )11 (dmso)11 ](O3 SCH=CH2 )⋅3 DMSO (4), is available as the main product. Starting from the hexanuclear bismuth oxido nitrate, another cluster, [Bi38 O45 (NO3 )8 (O3 SCH=CH2 )14 (dmso)18 ](O3 SCH=CH2 )2 ⋅2 DMSO (5), was observed as a co-crystallizing side product, which upon further hydrolysis afforded [Bi38 O45 (NO3 )6 (OH)4 (O3 SCH=CH2 )12 (dmso)23 (H2 O)2 ](O3 SCH=CH2 )2 ⋅2 H2 O (6).

[Immunotherapy Against Head and Neck Cancer Stem Cells]. / Immuntherapie gegen Tumorstammzellen bei Plattenepithelkarzinomen im Kopf-Hals-Bereich.

Immunotherapy against head and neck cancer stem cells Immunologic therapies like antibodies in solid tumors like squamous cell cancer of the head and neck are administered either alone or in combination with radiation and chemotherapy. Despite some respectable successes, the effect of this therapy reaches its limits due the ability of the tumor to escape the immune system. Cancer stem cells seem to play an important role in this process due to their intrinsic resistance to conventional therapy and the ability to regenerate tumor heterogeneity. This way they substantially contribute to the formation of recurrences and metastases. Therefore, future immunotherapies should target specifically this subpopulation, possibly in combination with other therapeutic modalities. In this review the immunologic features of cancer stem cells and their potential as target for immunotherapies is summarized.

Diet-induced phenotypic plasticity in European eel (Anguilla anguilla).

Two phenotypes are present within the European eel population: broad-heads and narrow-heads. The expression of these phenotypes has been linked to several factors, such as diet and differential growth. The exact factors causing this dimorphism, however, are still unknown. In this study, we performed a feeding experiment on glass eels from the moment they start to feed. Eels were either fed a hard diet, which required biting and spinning behavior, or a soft diet, which required suction feeding. We found that the hard feeders develop a broader head and a larger adductor mandibulae region than eels that were fed a soft diet, implying that the hard feeders are capable of larger bite forces. Next to this, soft feeders develop a sharper and narrower head, which could reduce hydrodynamic drag, allowing more rapid strikes towards their prey. Both phenotypes were found in a control group, which were given a combination of both diets. These phenotypes were, however, not as extreme as the hard or the soft feeding group, indicating that some specimens are more likely to consume hard prey and others soft prey, but that they do not selectively eat one of both diets. In conclusion, we found that diet is a major factor influencing head shape in European eel and this ability to specialize in feeding on hard or soft prey could decrease intra-specific competition in European eel populations.

Epidemiology of laryngeal carcinoma in Germany, 1998-2011.

Constituting 25-30 % of all head and neck cancer cases, laryngeal carcinoma is the most prevalent entity. Major risk factors of laryngeal cancer are smoking and excessive alcohol consumption. This study presents the recent developments in the incidence of laryngeal cancer from 1998 to 2011 in Germany. Laryngeal carcinoma was identified using International Statistical Classification of Diseases and Related Health Problems (ICD10) from German population-based cancer registries. The incidence was provided by the Robert Koch Institute, and the mortality data were derived from German death statistics for further evaluation. Both descriptive and analytical analyses were conducted. From 1998 to 2011, a total of 14,847 laryngeal carcinoma cases were reported, in 13,195 men and 1652 women. Glottic carcinoma represented the main entity, constituting 69 % of male cases and 50 % of female cases. For men, a decline in incidence was observed starting in 2006. The incidence rate for women remained stable for the period of observation. The incidence of laryngeal cancer resembles the development of smoking behaviour in Germany. To maintain the positive trend of the male population and to reduce the incidence in women, it is crucial to continue and to improve the prevention of smoking campaigns in Germany.

Intensity modulated perioperative HDR brachytherapy for recurrent and/or advanced head and neck metastases.

Recurrent neck metastases following surgery and full dose adjuvant radiotherapy of squamous cell head and neck cancer remain a clinical challenge. After revision neck dissection and chemotherapy re-irradiation dosage is often limited and survival prognosis deteriorates. Here, adjuvant high-dose rate intensity modulated perioperative brachytherapy (HDR IMBT) offers a second full radiation dose with a limited volume of normal tissue radiation in the neck. In this retrospective study patients were identified who underwent revision surgery and perioperative HDR IMBT for recurrent neck metastases. Survival rates were estimated and the scarce literature on interstitial brachytherapy of the neck was reviewed. From 2006 to 2014, nine patients were treated for recurrent or palliative neck metastases using salvage surgery and HDR IMBT. Eight patients received previous surgery and external beam radiotherapy with or without chemotherapy. Two and five year overall survival was calculated to be 78 and 67 %, respectively. HDR IMBT is a salvage treatment option for selected cases in the neck following surgical revision or last-line treatment strategies. In the literature and this small cohort radiation toxicity and the risk of "carotid blow-out" seemed to be low.

Tris(3,5-dimethylpyrazolyl)methane-based heterobimetallic complexes that contain Zn - and Cd - transition-metal bonds: synthesis, structures, and quantum chemical calculations.

Reactions of the tris(3,5-dimethylpyrazolyl)methanide amido complexes [M'{C(3,5-Me2 pz)3 }{N(SiMe3 )2 }] (M'=Mg (1 a), Zn (1 b), Cd (1 c); 3,5-Me2 pz=3,5-dimethylpyrazolyl) with two equivalents of the acidic Group 6 cyclopentadienyl (Cp) tricarbonyl hydrides [MCp(CO)3 H] (M=Cr (2 a), Mo (2 b)) gave different types of heterobimetallic complex. In each case, two reactions took place, namely the conversion of the tris(3,5-dimethylpyrazolyl)methanide ligand (Tpmd*) into the -methane derivative (Tpm*) and the reaction of the acidic hydride M = H bond with the M' = N(SiMe3 )2 moiety. The latter produces HN(SiMe3 )2 as a byproduct. The Group 2 representatives [Mg(Tpm*){MCp(CO)3 }2 (thf)] (3 a/b) form isocarbonyl bridges between the magnesium and chromium/molybdenum centres, whereas direct metal-metal bonds are formed in the case of the ions [Zn(Tpm*){MCp(CO)3 }](+) (4 a/b; [MCp(CO)3 ](-) as the counteranion) and [Cd(Tpm*){MCp(CO)3 }(thf)](+) (5 a/b; [Cd{MCp(CO)3 }3 ](-) as the counteranion). Complexes 4 a and 5 a/b are the first complexes that contain Zn - Cr, Cd - Cr, and Cd - Mo bonds (bond lengths 251.6, 269.8, and 278.9 pm, respectively). Quantum chemical calculations on 4 a/b* (and also on 5 a/b*) provide evidence for an interaction between the metal atoms.

Occurrence of Alternaria secondary metabolites in milling oats and its de-hulled fractions from harvest years 2017 to 2021.

In this study, secondary metabolites produced by Alternaria were investigated for their presence in milling oats. For this purpose, pre-cleaned milling oat samples (n = 193), intended for human consumption, out of harvest years 2017 to 2021 originating from different northern European countries were analysed by LC-MS/MS. Alternariol and alternariol methyl ether were positively identified in 38% of the samples with mean values of 2.1 µg/kg and 1.2 µg/kg, respectively. The highest concentrations of 50.5 µg/kg alternariol and 24.2 µg/kg of alternariol methyl ether were detected in a Latvian sample. Tenuazonic acid was found in 45% of all samples, with a mean concentration of 28.9 µg/kg and a maximum concentration of 1430 µg/kg, also in a Latvian sample. Tentoxin was detected in 49% of all samples with a mean value of 1.7 µg/kg. The Alternaria metabolite most frequently detected in 96% of all samples was infectopyrone with a mean concentration of 593 µg/kg and a maximum value reaching up to 3990 µg/kg in a German sample. In addition, eight oat samples were selected to investigate to what extent the Alternaria metabolites are distributed between the oat hulls and the oat kernels. After de-hulling, approximately 23% of Alternaria metabolites were found in the remaining oat kernels. According to the results, alternariol, infectopyrone and altersetin were present in the kernels with the lowest proportion of 10%-20% on average, respectively. The values for tentoxin showed that about 60% of tentoxin was contained in the hulls, while almost 40% remained in the oat kernel. This suggests that potential health risks posed by Alternaria secondary metabolites and metabolites of other fungal genera in milling oats can be reduced by de-hulling.

On the solution behaviour of benzyllithium·(-)-sparteine adducts and related lithium organyls--a case study on applying 7Li,15N{1H} HMQC and further NMR methods, including some investigation into asymmetric synthesis.

2D (7)Li,(15)N heteronuclear shift correlation through scalar coupling has successfully been applied to several lithium organyls consisting of polydentate N ligands such as N,N,N',N'-tetramethylethylenediamine (tmeda), N,N,N',N',N''-pentamethyldiethylentriamine (pmdta) and (-)-sparteine. Structural insights on the conformation of benzyllithium·pmdta (5) in a toluene solution and the strength of ion pairing in combination with PGSE NMR measurements, (1)H,(1)H-NOESY and (1)H,(7)Li-HOESY experiments are presented. By studying in detail the formation of 5 in solution, a transient species has been observed for the first time and assigned to a pre-complex of nBuLi and pmdta. In addition, the solution behaviour of the complex formed between benzyllithium and (-)-sparteine (8) has been studied by PGSE and multinuclear NMR spectroscopy. The straightforward synthesis and first applications in asymmetric lithiations are also reported, which show that the new system benzyllithium·(-)-sparteine (8) provide poorer enantioselective induction than the classical nBuLi·(-)-sparteine (6). The results were supported by deprotonation experiments confirming that the formation of 8 relies on two relevant factors, namely temperature and lithiating reagent. The existence of 8 may thus interfere with the asymmetric induction when the system nBuLi· (-)-sparteine is used in the enantioselective deprotonations of N-Boc-N-(p-methoxyphenyl)-benzylamine conducted in toluene.

Round-Window Vibroplasty: Systematic Review and Meta-Analysis of Audiological Effectiveness With Different Round-Window Coupling Techniques.

OBJECTIVE: Active middle ear implants can be directly coupled to the round-window (RW) membrane via RW Vibroplasty. The objectives of this systematic review were to summarize data on different RW coupling techniques and to investigate their effect on audiological and safety outcomes using meta-analyses. DATABASES REVIEWED: PubMed (MEDLINE), Cochrane Library, and Embase (DIMDI). METHODS: All publications reporting on audiological outcomes in human patients after RW Vibroplasty were included. Two independent reviewers carried out screening and data extraction. Meta-analyses and meta-regression were used to evaluate the potential effects of surgical and demographic parameters on primary audiological outcomes. Adverse events were extracted and tabulated for qualitative analysis. RESULTS: Fourteen different combinations of surgical coupling parameters were identified in 61 included publications. Overall, data from 23 publications could be used for meta-analyses. Significantly better aided sound-field thresholds were reported for RW Vibroplasty performed without a dedicated coupler and using fascia as interponate, compared with RW Vibroplasty with an RW coupler or without an interponate. These effects were not found in other outcomes (i.e., functional gain, word recognition score). Reporting of adverse events was relatively heterogeneous, with 32 explicit mentions of revision surgery after the loss of coupling efficacy. CONCLUSION: There are numerous publications investigating the effectiveness of coupling active middle ear implants to the RW membrane. However, studies are typically undersampled and of low evidence level. Using meta-analyses, weighted means, and qualitative analyses enabled a summary of the existing literature on audiological and safety outcomes after RW Vibroplasty. Individual selection of the most appropriate coupling modality with standardized intraoperative measurement and careful patient follow-up may be considered key factors for achieving effective RW coupling.

Optimal timing for antimicrobial prophylaxis to reduce surgical site infections: a retrospective analysis of 531 patients.

It has been revealed that the administration of an antimicrobial prophylaxis (AP) reduces the rate of surgical site (SSI) following colorectal cancer surgery. Nevertheless, the optimal timing of this medication remains unclear. The aim of this study was to determine more precisely the optimal time for administering antibiotics and to see if this could reduce the number of possible surgical site infections. The files of individuals who underwent colorectal cancer surgery at the University Hospital Brandenburg an der Havel (Germany) between 2009 and 2017 were analyzed. Piperacillin/tazobactam, cefuroxime/metronidazole and mezlocillin/sulbactam were administered as AP regimens. Timing of AP was obtained. The primary objective was the rate of SSIs based on CDC criteria. Multivariate analysis took place to identify risk factors for SSIs. A total of 326 patients (61.4%) received an AP within 30 min, 166 (31.3%) between 30 and 60 min, 22 (4.1%) more than 1 h before surgery, and 15 (2.8%) after surgery. In 19 cases (3.6%) a SSI occurred during hospital stay. A multivariate analysis did not identify AP timing as a risk factor for the occurrence of SSIs. With significance, more surgical site occurrences (SSO) were diagnosed when cefuroxime/metronidazole was given. Our results suggest that AP with cefuroxime/metronidazole is less effective in reducing SSO compared with mezlocillin/sulbactam and tazobactam/piperacillin. We assume that the timing of this AP regimen of < 30 min or 30-60 min prior to colorectal surgery does not impact the SSI rate.

Evaluation and development of a predictive model for ultrasound-guided investigation of neck metastases.

Ultrasound investigations for the correct identification of lymph node metastases depend on the experience and qualifications of the investigator; thus, model that provides better preoperative evaluation is desired. Data from 290 patients with an upcoming neck dissection were analyzed to compare the preoperative ultrasound assessment of neck metastases with the pathologically proven postoperative neck status. In total, 364 data sets with 200 malignant and 164 benign lymph nodes were explored. The minimal and maximal transverse diameters and their ratio were shown to be especially good parameters for sensitivity, whereas the echostructure and the presence of a hilum were good for specificity. A model incorporating the evaluated markers is presented. The model provides better judgement of neck lymph nodes in a more objective manner. Using logistic regression, five parameters were identified to predict metastases.