The Superficial Anastomosing Veins of the Human Brain Cortex: A Microneurosurgical Anatomical Study

Introduction: In this microneurosurgical and anatomical study, we characterized the superficial anastomosing veins of the human brain cortex in human specimens.Material and Methods: We used 21 brain preparations fixed in formalin (5%) that showed no pathological changes and came from the autopsy sections. The superficial veins were dissected out of the arachnoid with the aid of a surgical microscope.Results: We dissected nine female and 12 male brain specimens, with an average age of 71 ± 11 years (range 51–88 years). We classified the superficial veins in five types: (I) the vein of Trolard as the dominat vein; (II) the vein of Labbé as the dominant vein; (III) a dominant sylvian vein group, and the veins of Trolard and Labbé nonexistent or only rudimentary present without contact to the Sylvian vein group; (IV) very weak sylvian veins with the veins of Trolard and Labbé codominant; and V) direct connection of Trolard and Labbé bypassing the Sylvian vein group. The vein of Trolard was dominant (Type I) in 21.4% and the vein of Labbé (Type II) in 16.7%. A dominant sylvian vein group (Type III) was found in 42.9%. Type IV and Type V were found in 14.3 and 4.7% respectively.Conclusion: No systematic description or numerical distribution of the superior anastomotic vein (V. Trolard) and inferior anastomotic vein (V. Labbé) has been found in the existing literature. This study aimed to fill this gap in current literature and provide data to neurosurgeons for the practical planning of surgical approaches.

Novel Fluoridoaluminates from Ammonothermal Synthesis: Two Modifications of K2AlF5 and the Elpasolite Rb2KAlF6

Two new modifications of the pentafluoridoaluminate K2AlF5 were obtained from ammonothermal synthesis at 753 K, 224 MPa and 773 K, 220 MPa, respectively. Both crystallize in the orthorhombic space group type Pbcn, with close metric relations and feature kinked chains of cis-vertex-connected AlF6 octahedra resulting in the Niggli formula ∞1{[AlF2/2eF4/1t]2−}. The differences lie in the number of octahedra necessary for repetition within the chains, which for K2AlF5-2 is realized after four and for K2AlF5-3 after eight octahedra. As a result, the orthorhombic unit cell for K2AlF5-3 is doubled in chain prolongation direction [001] as compared to K2AlF5-2 (1971.18(4) pm versus 988.45(3) pm, respectively), while the unit cell parameters within the other two directions are virtually identical. Moreover, the new elpasolite Rb2KAlF6 is reported, crystallizing in the cubic space group Fm3¯m with a = 868.9(1) pm and obtained under ammonothermal conditions at 723 K and 152 MPa.

SHIP MANOEUVRING PREDICTION BASED ON NUMERICAL TOWING TANK TECHNIQUE

A practical procedure is proposed in this paper to predict ship manoeuvrability. A three degrees of freedom MMG (Japanese Manoeuvring Mathematical Modelling Group)-type model is established to simulate rudder manoeuver. Propeller thrust and rudder loads are calculated by empirical formulas, whereas the hull forces as well as moment are determined with hydrodynamic derivatives which are derived from CFD (Computational Fluid Dynamics) computations. An own developed RANS (Reynolds-Averaged Naiver-Stokes) solver on the base of OpenFOAM is applied to simulate a range of PMM (Planar Motion Mechanism) tests and Fourier analyses of the computed results are carried out to obtain the required derivatives. In order to demonstrate the effectivity of the whole procedure and the RANS computations, the US (United States) combatant DTMB 5415 is taken as a sample for an application. Forced motions of surge, sway, yaw and yaw with drift for the bare hull with bilge keels are simulated. Thereafter, simulations of standard rudder manoeuvers, i.e. turning and zigzag, are performed by applying the computed derivatives. The results are compared with available measured data. It has been shown that the present procedure together with the RANS method can be used to evaluate the manoeuvrability of a ship since general good agreements between the simulated results and measured data are achieved.

The Effectiveness of Concept Teaching Using Concept Maps on Academic Achievement and Elimination of Misconceptions: Protein Synthesis Case

This study aimed to analyze the effectiveness of concept maps on the academic achievements of Biology teacher candidates and the elimination of misconceptions comparing the method with the traditional rote learning method. The quasi-experimental design, specifically, the pre-test post-test control group type was used in this research to address the research questions. The research was carried out with 60 Biology teacher candidates. Achievement test and diagnostic test were used as data collection tools throughout the research. SPSS version 20 software was used to analyze the obtained quantitative data. Independent samples t-test was used to determine whether there was a significant difference between the control and experimental group students’ level of prior knowledge regarding the subject of protein synthesis. The findings revealed no statistically significant difference between the groups in pre-test (ρ > .05). However, the findings revealed a statistically significant difference between the groups, in the post-test, in favor of the concept map method used for the experiment group (ρ < .05). The increase in the post-test scores of the experiment group students indicated that the teaching method based on concept maps positively affected the students' academic achievement and elimination of misconceptions. Research indicated that students could not establish a correct relationship between the concepts of DNA, RNA, mRNA, tRNA, rRNA, nucleus, chromosome, gene, genetic code, codon, anti-codon, translation, transcription, ribosome, protein, and amino acid terms taught in protein synthesis subject. It was concluded that the areas of use for concept maps should not be limited as a teaching tool, but should be further extended to for determining misconceptions, eliminating misconceptions, and evaluating the instruction.

Development of a Staff Informant Measure of Lucidity

Lucidity Measure Development: An existing questionnaire measuring lucidity length, degree, content, coinciding circumstances, and time from lucid episode to death was expanded to include time of day, expressive and receptive communication and speech the month prior to and during the lucid event. Pilot Study: 33 interviews with staff were conducted; 73% reported ever witnessing paradoxical lucidity. Among 29 events reported, 31% lasted several days, 20.7%, 1 day, and 24.1% less. In 78.6% the patient engaged in unexpected activity. 20% died within 3 days and 17% within 3 months after the event. Qualitative Analyses: To refine the measure, 10 family caregivers and 20 LTSS staff caregivers completed a web-based focus-group type exercise using QualtricsXM. A content-thematic analysis with an inductive approach was applied to make qualitative inferences by analyzing the meaning and semantic relationship of words, phrases, and concepts. Using the reduction method of selection, conceptual content categories will be developed.

P-BN02 Experience in Transitioning From Laparoscopic to Robotic-Assisted ParaEsophageal Hernia Repair - A Single Centre Experience

Background Paraesophageal hernias (PEH) constitute only 5% of hiatal hernias. They may give rise to significant post-prandial symptoms, acute episodes of obstruction or gastric ischaemia and patient mortality. Surgical repair of symptomatic PEHs is the current standard of care. This study explores our centre’s experience with the introduction of Robotic Assisted PEH (RA-PEH) repair in comparison to our longer established technique of laparoscopic repair. Methods Retrospective review of all laparoscopic and robotic PEH repair using the DaVinci Xi between January 2017 and May 2020 by a single surgeon in 2 institutions. A total of 27 cases were included in our review. An analysis of patient demographics, operative time and approach, morbidity and mortality was performed. Results Sixteen patients underwent laparoscopic repairs and 11 underwent elective robotic repair. Fundoplication was performed in both groups while mesh repair was used in 18% of the laparoscopy group. Type IV hiatal hernia was found in 50% and 37% in the laparoscopy and RA-PEH groups, respectively. Mean operative time was 144 minutes in the laparoscopy group and 153 minutes for RA-PE (p = 0.07). Median length of stay was 2 days for both groups (p = 0.18). Post-operative morbidity occurred in 37% and 9% in the laparoscopy and RA-PEH groups respectively (p = 0.18). There was 1 case of acute post-operative recurrence and re-operation in the laparoscopy group. Conclusions Minimally invasive surgery is the standard of treatment in PEH repair. The robotic technique is a safe and effective approach when compared to the standard laparoscopic repair. It may have an advantage in reducing reliance on the necessity of having experienced assistance in the operating theatre without utilising more theatre time.