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Surgical site infections (SSIs) after neurosurgery are potentially life-threatening and entail great costs. SSIs may occur from airborne bacteria in the operating room, and ultraclean air is desired during infection-prone cleaning procedures. Door openings and the number of persons present in the operating room affect the air quality. Mobile laminar airflow (MLAF) units, with horizontal laminar airflow, have previously been shown to reduce airborne bacterial contamination.To assess the effect of MLAF units on airborne bacterial contamination during neurosurgical procedures.In a quasi-experimental design, bacteria-carrying particles (colony-forming units: cfu) during neurosurgical procedures were measured with active air-sampling in operating rooms with conventional turbulent ventilation, and with additional MLAF units. The MLAF units were shifted between operating rooms monthly. Colony-forming unit count and bacterial species detection were conducted after incubation. Data was collected for a period of 18 months.A total of 233 samples were collected during 45 neurosurgical procedures. The use of MLAF units significantly reduced the numbers of cfu in the surgical site area (P 0.001) and above the instrument table (P 0.001). Logistic regression showed that the only significant predictor affecting cfu count was the use of MLAF units (odds ratio: 41.6; 95% confidence interval: 11.3-152.8; P 0.001). The most frequently detected bacteria were coagulase-negative staphylococci.MLAF successfully reduces cfu during neurosurgery to ultraclean air levels. MLAF units are valuable when the main operating room ventilation system is unable to produce ultraclean air in infection-prone clean neurosurgery.

A non-toxic hydrolytically fast-degradable antibacterial hydrogel is herein presented to preemptively treat surgical site infections during the first crucial 24 h period without relying on conventional antibiotics. The approach capitalizes on a two-component system that form antibacterial hydrogels within 1 min and consist of i) an amine functional linear-dendritic hybrid based on linear poly(ethylene glycol) and dendritic 2,2-bis(hydroxymethyl)propionic acid, and ii) a di-N-hydroxysuccinimide functional poly(ethylene glycol) cross-linker. Broad spectrum antibacterial effect is achieved by multivalent representation of catatonically charged β-alanine on the dendritic periphery of the linear dendritic component. The hydrogels can be applied readily in an in vivo setting using a two-component syringe delivery system and the mechanical properties can accurately be tuned in the range equivalent to fat tissue and cartilage (G' = 0.5-8 kPa). The antibacterial effect is demonstrated both in vitro toward a range of relevant bacterial strains and in an in vivo mouse model of surgical site infection.

This study examines aspects of prediction of suicide and death of undetermined intent. We investigated all consecutive, autopsied patients between 1993 and 1997 who had been in contact with the Addiction Centre in Malmo from 1968 onwards. The staff was asked, shortly after autopsy but before they knew of the manner of death, if they thought the patient had committed suicide. The case records were blindly evaluated, and toxicological autopsy findings for alcohol in blood samples investigated. The specificity of prediction was 83% and significantly more often correct than the sensitivity, which was only 45% for suicide and for suicide/death of undetermined intent (93% versus 39%). Suicidal communication was more often considered non-serious before death of undetermined intent than before suicide. The former could be predicted by ideation but not by suicide attempt reported in case records, unlike suicide, which was predicted by both. The undetermined group also showed higher levels of alcohol in the blood at autopsy. We concluded that more serious clinical investigation of suicidal feelings, which may be hidden and not taken seriously, and treatment of alcohol use disorders with active follow-up appear urgent in the efforts to prevent suicide.

Objectives: Several studies have shown mortality and suicide risk in substance use disorders, and autopsy findings with respect to the used substances. However, there seems to be a gap in the knowledge about substances misused in life and at death at the within-person level. Methods: All consecutive, autopsied patients during 1993 to 1997, who had been in contact with the Addiction Centre in Malm&ouml, from 1968, were investigated (365 subjects). Drug misuse in the long-term course noted in case records was related to autopsy findings. Self-inflicted death (suicide/undetermined suicide/accidental overdose) was compared with natural death. Results: Benzodiazepine misuse was associated with a high risk of autopsy findings of the substance in suicide and death of undetermined intent. It was also associated among non-misusers, but less so. An alcohol level above 1&permil, was found more often in self-inflicted death. Prescription opioids at autopsy were mainly found in self-inflicted death among non-misusers. Heroin misuse was related to overdose. Central nervous system stimulants (CNS-S) and cannabis were rarely found in self-inflicted death among previous misusers. The overlap between depression in life and antidepressants at death was low. Conclusions: Benzodiazepines and alcohol seem to disinhibit suicidal tendencies. Suicide risk among users of cannabis and CNS-S may be related to other risk factors than acute use. Implications for suicide prevention are discussed.

Engineered surfaces with nanoscale features of gold on silicon or glass have recently been used to improve the understanding of adhesion-mediated environmental sensing of cells. Often such surfaces present a cell-binding ligand, such as arginine–glycine–aspartic acid (RGD) peptide motifs, at controlled intramolecular distances on an inert background surface such as polyethylene glycol (PEG). The adhesion mechanism of macromolecular ligands in which direct interaction with cells is nonspecific is not known and the cell response is dictated by the type and the concentration of proteins adsorbed from solution. Dendrimers may increase the availability and multivalency of cell-interacting ligands as a consequence of their branched shape and inherently high concentration of end groups. It is therefore interesting to examine the eventual effect of the macromolecular architecture on the cell viability by the controlled reduction of ligands on a surface. Herein, we demonstrate the fabrication of selfassembledmacromolecular hybrid arrays in which the relative position of two anionic macromolecules of different architectures—a carboxy-functionalized dendrimer and a linear polymer—is straightforwardly controlled on a PEG surface. We also show how the interaction of primary human endothelial cells with these surfaces is modulated by the molecular spacing and how protein binding to the macromolecular arrays can be evaluated by using a standard surface plasmon resonance (SPR) technique. Self-assembled, short-range-ordered Au nanoparticle (NP) arrays were used as a versatile template to arrange polymeric entities at the nanometer scale (Figure 1a). This

Thermosetting resins based on semi-crystalline poly(dimethyl trimethylene carbonate) (PDTC) were synthesised and characterised. Polymers with linear and branched architectures were synthesised thro ...

Recently, matrices based on oligomers of dioxin and thiophene (polymer-assisted laser desorption/ionization (PALDI)) have been described for mass spectrometric (MS) analysis of low molecular weight compounds (Woldegiorgis A, von Kieseritzky F, Dahlstedt E, Hellberg J, Brinck T, Roeraade J. Rapid Commun. Mass Spectrom. 2004; 18: 841-852). In this paper, we report the use of PALDI matrices for low molecular weight polymers. An evaluation with polystyrene and polyethylene glycol showed that no charge transfer ionization occurs. Ionization is mediated through metal ion adduction. Comparison of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) data for two very low molecular weight polymers with data obtained from size-exclusion chromatography (SEC) revealed a systematic difference regarding mean molecular weight and dispersity. Further, the mass spectra obtained with PALDI matrices had a higher signal-to-noise ratio than the spectra obtained with conventional matrices. For polymers with higher molecular weights (>1500 Da), the conventional matrices gave better performance. For evaluation of the MALDI spectra, three non-linear mathematical models were evaluated to model the cumulative distributions of the different oligomers and their maximal values of Mw, Mn and PDI. Models based on sigmoidal or Boltzmann equations proved to be most suitable. Objective modeling tools are necessary to compare different sample and instrumental conditions during method optimization of MALDI analysis of polymers, since the bias between MALDI and SEC data can be misleading.

Summary: Branched aliphatic polycarbonates were synthesized by ring opening polymerization of 5,5-dimethyl-1,3-dioxane-2-one (NPC) initiated from polyfunctional alcohols and a commercial hyperbranched polyester (BOLTORN®). Polymerizations in the presence of fumaric acid under bulk conditions allowed high conversion (80%) without gelation. The synthesis of polymers with long chain branches was confirmed by size exclusion chromatography and universal calibration. The Mark–Houwink exponent decreased, indicating an increased density, while increasing the number of arms. The star polymers with up to four arms showed thermal properties Tg (20–30 °C) and Tm (100–110 °C) similar to linear PNPC. Boltorn™ hyperbranched polymer with radial polycarbonate grafts.

Three sets of aliphatic polyester dendrimers based on 2,2-bis(methylol)propionic acid (bis-MPA) were synthesized. Two of the sets had benzylidene terminal groups and either a trimethylolpropane or ...

The antibiotic resistance developed among several pathogenic bacterial strains has spurred interest in understanding bacterial adhesion down to a molecular level. Consequently, analytical methods that rely on bioactive and multivalent sensor surfaces are sought to detect and suppress infections. To deliver functional sensor surfaces with an optimized degree of molecular packaging, we explore a library of compact and monodisperse dendritic scaffolds based on the nontoxic 2,2-bis(methylol)propionic acid (bis-MPA). A self-assembled dendritic monolayer (SADM) methodology to gold surfaces capitalizes on the design of aqueous soluble dendritic structures that bear sulfur-containing core functionalities. The nature of sulfur (either disulfide or thiol), the size of the dendritic framework (generation 1-3), the distance between the sulfur and the dendritic wedge (4 or 14 Å), and the type of functional end group (hydroxyl or mannose) were key structural elements that were identified to affect the packaging densities assembled on the surfaces. Both surface plasmon resonance (SPR) and resonance-enhanced surface impedance (RESI) experiments revealed rapid formation of homogenously covered SADMs on gold surfaces. The array of dendritic structures enabled the fabrication of functional gold surfaces displaying molecular covering densities of 0.33-2.2 molecules·nm(-2) and functional availability of 0.95-5.5 groups·nm(-2). The cell scavenging ability of these sensor surfaces for Escherichia coli MS7fim+ bacteria revealed 2.5 times enhanced recognition for G3-mannosylated surfaces when compared to G3-hydroxylated SADM surfaces. This promising methodology delivers functional gold sensor surfaces and represents a facile route for probing surface interactions between multivalently presented motifs and cells in a controlled surface setting.

The development of new adhesive wound care products intended for an application over a prolonged time requires good water transporting properties of the adhesive for the maintenance of a suitable environment around the wound. The ability of polydimethylsiloxane (PDMS)-based silicone films to transport water has led to its use in skin pressure-sensitive adhesives and it would be advantageous to find ways for controlling or increasing water transport across PDMS films in order to be able to develop improved skin adhesives. In this study we present a way to increase water transport in such films by the addition of hydrophilic excipients. Three hydrophilic additives, highly water-soluble sucrose and the two superabsorbent polymers (SAP) Carbopol® and Pemulen™, were investigated. The effect of the excipients was characterized by water transport studies, swelling tests, scanning electron microscopy imaging and confocal microscopy. The cross-linked polymers, primarily Pemulen™, were efficient water transport enhancers, whereas sucrose did not show any effect. The effect of the additives seemed to correlate with their water binding capacity. For SAPs the formation of a percolating structure by swollen polymer was also suggested, which enhances water penetration by the higher volume fraction of areas with a higher diffusion constant (swollen SAP), leading to a faster transport through the entire film. Refereed/Peer-reviewed

Background Substance use disorders have repeatedly been found to lead to premature death, i.e. drug-related death by disease, fatal intoxications, or trauma (accidents, suicide, undetermined suicide, and homicide). The present study examined the relationship between multi-drug substance use and natural and unnatural death. Methods All consecutive, autopsied patients who had been in contact with the Addiction Centre in Malmö University Hospital from 1993 to 1997 inclusive were investigated. Drug abuse was investigated blindly in the case records and related to the cause of death in 387 subjects. Results Every substance apart from alcohol used previously in life added to the risk of unnatural death in a linear way. There were independent increased risks of fatal heroin overdoses or undetermined suicide. Death by suicide and violent death were unrelated to additional abuse. Conclusion The number of drugs used was related to an increased risk of unnatural death by undetermined suicide (mainly fatal intoxications) and heroin overdose.

Recently, matrices based on oligomers of dioxin and thiophene (polymer-assisted laser desorption/ionization (PALDI)) have been described for mass spectrometric (MS) analysis of low molecular weight compounds (Woldegiorgis A, von Kieseritzky F, Dahlstedt E, Hellberg J, Brinck T, Roeraade J. Rapid Commun. Mass Spectrom. 2004; 18: 841-852). In this paper, we report the use of PALDI matrices for low molecular weight polymers. An evaluation with polystyrene and polyethylene glycol showed that no charge transfer ionization occurs. Ionization is mediated through metal ion adduction. Comparison of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) data for two very low molecular weight polymers with data obtained from size-exclusion chromatography (SEC) revealed a systematic difference regarding mean molecular weight and dispersity. Further, the mass spectra obtained with PALDI matrices had a higher signal-to-noise ratio than the spectra obtained with conventional matrices. For polymers with higher molecular weights (1500 Da), the conventional matrices gave better performance. For evaluation of the MALDI spectra, three non-linear mathematical models were evaluated to model the cumulative distributions of the different oligomers and their maximal values of Mw, Mn and PDI. Models based on sigmoidal or Boltzmann equations proved to be most suitable. Objective modeling tools are necessary to compare different sample and instrumental conditions during method optimization of MALDI analysis of polymers, since the bias between MALDI and SEC data can be misleading.

A computer software, RattsBASE (RB), was developed for all forensic pathology units in Sweden and introduced in 1992. Simultaneously, a corresponding software, ToxBASE (TB), was developed for the Department of Forensic Toxicology, where all forensic toxicology in Sweden is managed. Both of the databases were created using dBASE IV, and the programming was carried out according to specifications from the staff at the forensic toxicology and forensic pathology units. Since the development of RB and TB was coordinated, the sysetems can run together smoothly. The purpose of both systems was to automate the offices and to enable compilation of detailed statistics. Installation of Novell Netware and ISDN-connections (Integrated Service Digital Network) has enabled rapid communication between the units and easy compilation of nationwide statistics of forensic pathology and forensic toxicology. The systems offer a wide spectrum of reports and include a simple module for evaluation of the importance of the forensic efforts for the whole death investigation. The configuration of the softwares has also enabled processing of a large amount of related toxicological and autopsy data that in turn has yielded a base for compilation of toxicology interpretation lists. This article includes a summary of the features of the software and a discussion of its benefits and limitations.

A facile methodology for the fabrication of functional crosslinked three dimensional (3D) networks has herein been explored via the benign and UV initiated thiol–ene coupling (TEC) chemistry. The careful selection of monomers or polymers and their feed ratio resulted in straightforward design of organic, inorganic and hydrogel networks with readily available alkenes or thiol functional groups. All crosslinked networks were fabricated within 1 second of UV exposure at wavelengths of 320–390 nm and generally exhibited excellent gel fractions around 90%. By introducing off-stoichiometric thiol and ene (OSTE) monomer feed ratios the window of mechanical properties could be manipulated. For the organic triazine system, the Young's modulus was altered from 780 MPa at an equimolar monomer ratio to soft 106 kPa for 2.5 equiv. with excess of thiol compared to enes. Postfunctionalizations with hydrophilic polyethylene glycols or acrylic acid and hydrophobic heneicosafluorododecyl acrylate were explored for the manipulation of functional networks. In this case, the rigid networks with excess of thiols were used as model substrates of which the initial contact angle (CA) of 60° was decreased to 43° by the introduction of acrylic acid and increased to 140° by successful attachment of fluorinated molecules. Finally, amalgamating micropatterning strategy with simple postfunctionalizations of hydrophobic groups resulted in superhydrophobic rigid surfaces with a CA of 173°.

Orthogonally functionalized PEGs displaying alkenes and azides have been prepared and their dual-purpose scaffolding potential was exploited via click chemistry for controlled insertion of biorelevant moieties as well as facile fabrication of soft, non-toxic and degradable hydrogels.

The purpose of this study was to investigate the prevalence of toxic agents in attempted and completed suicides. The purpose was also to explore the sources of the drugs taken by suicide attempters. Verbal information on drug intake was collected from 280 suicide attempters during 1987-1990 in the Lund-Orup catchment area. Information on the sources of the drugs was collected from 143 of these attempters. The study also includes toxicological screening from 73 fatal poisonings in southern Sweden during 1989. According to verbal information, the most common drugs used by suicide attempters were benzodiazepines (51%), analgesics (29%) and antidepressants (20%). In suicide attempters, diazepam and levomepromazine were reported more than expected from prescription data. Toxicological screenings of fatal poisonings showed that benzodiazepines were most common (55%), followed by analgesics (38%), mainly propoxyphene (29%) and antidepressants (30%), mainly amitriptyline (22%). Amitriptyline and diazepam were more commonly detected in completed suicides than expected from prescription data. The most common sources of drugs to attempted suicides were physicians, and especially psychiatrists. We therefore conclude that continuous information to physicians on drug overdose is important, and it is also important to introduce alternative strategies to prevent suicidal behaviour.

Synthesis of bis-4,5-diazafluoren-9-one silver(I) nitrate I (dafone = 4,5-diazafluoren-9-one) and the low temperature X-ray single crystal structure of [Ag(4,5-diazafluoren-9-one)2NO3], crystal form 1, and a re-determination of [Ag(4,5-diazafluoren-9-one)2]NO3·H2O, crystal form 2 are presented. Crystal form 1 has a distorted trigonal planar coordination geometry around Ag(I) with an N–Ag–N bond angle of 123.45(7)°. Crystal form 2 has a perfect linear coordination around Ag, with N–Ag–N 180.0°. Compound I was characterized by 1H-NMR, biological activity and ESI-MS in DMSO at room temperature. The biological activity was determined against 6 different resistant clinical isolates; two Gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and four Gram-negative (Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, and Salmonella sp.) in comparison with 15 known antibiotics used in the treatment of diabetic foot infections. Compound I showed broad spectrum activity against all the test organisms. P. mirabilis and S. aureus and K. pneumoniae were the most sensitive clinical isolates (MIC = 4, 6 and 4 μg ml−1, respectively). Three different hydrogels containing I or Ag2SO4 were prepared and the antimicrobial activity against Ps. aeruginosa (ATCC 15442) compared, showing more or less equal activity on a weight basis, but I seems to have a significant better performance per silver ion. The Ag(I) complex also binds more effectively to calf thymus DNA than the dafone ligand itself.

In construction of the eosphagojejunostomy after total gastrectomy, the EEA stapled (US Surgical Corporation, Norwalk, CT) and the two-layer interrupted 3-0 Dexon anastomoses are compared concerning the radiological appearance, breaking strength, circulation, and collagen concentration. Thirty female pigs were used. After total gastrectomy and Roux-en-Y preparation, the pigs were randomized to achieve sutured or stapled anastomoses. 141Ce-labeled microspheres were used for measurements of anastomotic blood flow. After the pigs were killed, the breaking strength of the anastomosis was recorded, the collagen content determined, and an anastomotic index calculated comparing two perpendicular diameters in the anastomosis and 5 cm above. Breaking strength, leakage frequency, and anastomotic index were the same in the two groups. One week after surgery, there was a significant increase in anastomotic circulation (p less than 0.05) in both the sutured and the stapled anastomoses compared to controls. Collagen increased equally with time in the two groups (p less than 0.01). The stapled esophagojejunostomy was faster to perform (20 min) than the sutured (28 min) (p less than 0.05).

In head-on collisions, loose items in the rear of the car, such as luggage or unrestrained back seat passengers can cause substantial loading on the back of the front seats. The purpose of this paper is to study if such loading increases the injury severity for the front seat occupants. Data were collected from all fatal automobile accidents for a period of 1 year in Sweden. Information was collected about the survivors as well as the decreased. Head-on collisions were selected, and the injuries of the front seat occupants were scored according to the Abbreviated Injury Scale (AIS) and the Injury Severity Score (ISS). In evaluating the injury severity, the collision energy was taken into account. The results indicate that belted front seat passengers sustain a higher injury risk with an unrestrained passenger in the back seat. These results are valid for collision speeds below 45 km/h.

In 91 cases where the cause of death was heart disease, digoxin, Mg and K concentrations in serum and ventricular myocardium were measured post mortem. Forty per cent were positive for digoxin in both serum and myocardium. The mean serum level was 5.1 +/- 2.4 nmol/l and the mean myocardial level was 42.6 +/- 27.5 ng/g. Correlation could be established between serum and myocardial concentrations of digoxin. There were statistically significant differences in serum as well as in myocardial digoxin levels in persons on 0.13 mg and 0.25 mg per day, respectively. Myocardial levels of Mg and K were low as generally found in persons with ischemic heart disease. There was no correlation between these levels and myocardial digoxin concentrations. Caution must be exercised in the assessment of digoxin results from cadaver samples because of the postmortem rise of digoxin serum concentrations. Considering this fact, the results still indicate that the prevalence of toxic digoxin concentrations might be more common than previously thought.

We describe a device for the simultaneous recording of the autopsy findings during the autopsy, thereby offering a convenient way of obtaining correct and timely autopsy reports.

Belt protected car occupants involved in head-on collisions do not seem to suffer as severe injuries as unembalmed cadavers subjected to comparable simulated head-on collisions. Therefore it has been questioned if cadavers constitute adequate test specimens for study of thoracic tolerances. This investigation compares injuries in safety belt wearing living and dead pigs which have been subjected to simulated head-on collisions on an acceleration track. Tests were performed on all 20 pigs (10 living and 10 dead). The arterial side of the circulatory system of the dead pigs was infused. The force in the safety belts, the intraaortic pressure, the impact velocity and the deceleration of the sled were recorded. The tests were high speed filmed. Post mortem examination of the pigs revealed differences in injury severity. Dead pigs more easily suffered rib fractures. Deformation of the rib cage due to stripping of the periosteum and laceration of surrounding tissue occurred mainly in the dead pigs. Laceration of intrathoracic blood vessels was seen in dead pigs while isolated heart lesions were seen only in living animals. The main cause of these differences in tolerance level seems to be post mortem changes of the mechanical properties of the different tissues. The results are valid for pigs but indicate that great care has to be excercised when results obtained from cadaver experiments are evaluated concerning thoracic tolerance.

The reason for the higher leakage frequency after low anterior resection compared with high resection is unexplained. With the development of stapling devices, we have a unique opportunity to investigate anastomotic healing during standardized conditions. In female pigs, six in each group, a high anterior resection was performed by resection of a 5-cm colon segment, 10 cm above the peritoneal fold, and low anterior resection was performed after resection of a 5-cm segment at the peritoneal fold and downward. Differences in healing parameters, i.e., blood flow, breaking strength, and radiologic and histologic appearance between low and high anterior resection, were evaluated. Two leakages occurred after low and none after high anterior resection. The anastomotic index was 0.37 (high) and 0.26 (low) (P less than 0.05). The breaking strength was higher in low resections; this might be due to the thicker wall. There were no differences in blood circulation between high and low anastomoses, but the blood flow was significantly higher in the anastomotic area in both groups. This is probably due to the inflammatory reaction taking place in the healing anastomoses. This study, performed in a standardized fashion with a stapler adjusted to wall thickness and size of the intestine, cannot, on the basis of microcirculation, explain why leakage is more common in lower anastomoses.

A gliding contusion in the acute phase is characterized by a streaklike hemorrhage of venous origin situated subcortically in a paramedial convolution. In later stages perivascular necrosis may develop. This type of injury is caused by head angular acceleration and is often seen in traffic casualties when the head has hit the steering wheel, the dashboard or the windshield. The deformation of the brain matter close to the superior sagittal sinus has been simulated by means of a mathematical viscoelastic model in order to clarify the genesis of the gliding contusions. The blood vessels in the brain matter will be strained as a consequence of the brain deformation which results from head angular acceleration. The highest values of the strain occur subcortically where the blood vessels are injured first. The tolerance levels for gliding contusions have been deter- mined. The calculations which were based on experiments regarding the dynamic properties of the superior cerebral veins and on two alternative injury criteria proposed, indicate that a gliding contusion is not likely to arise if the maximal angular acceleration does not exceed 4500 rad/sec' or the change in angular -velocity does not exceed 70_rad/sec. INTRODUCHON Lindenberg and Freytag (1960) have described exten- sive hemorrhages of traumatic origin which were sit- uated subcortically in the paramedial parts of the cer- ebral hemispheres. The hemorrhages were of venous nature and were considered to be caused by deforma- tion of the brain matter when the head was subjected to angular acceleration. The lesions were designated as gliding contusions. For consecutive autopsy mater- ial Voigt and Lawenhielm (1974) have demonstrated similar injuries in 25% of traffic casualties. Also in these cases a head angular acceleration had occurred. The hemorrhages were however not always as exten- sive as in the description by Lindenberg and Freytag (1960). They appeared 'as streaklike perivascular bleedings mostly found in the back aspect of the fron- tal superior gyrus and in the upper part of the anter- ior central convolution. The hemorrhages seemed to originate from intracerebral portions of the superior cerebral veins. In victims surviving more than one week areas with necrosis or perivascular glial scars often running deeply into the white matter could be found. Remarkably the peripheral layers of the brain cortex remained intact in spite of sometimes extensive injuries. Brain injuries due to head impact can be very com- plex. The gliding contusion may be part of such an injury pattern but may as well not be present. On the other hand gliding contusions can occur alone. Different mechanisms of origin probably account for these differences. Although lesions of the gliding con- tusion type are quite common in traffic accidents they have attracted little attention in the literature. There- fore an investigation to clarify the genesis of the glid- ing contusion and thereby make it possible to predict threshold levels was needed. * Received 15 Jffrzuury 1975.

A method for investigating stretching of small blood vessels is presented. Stress and strain properties of the isolated parasagittal bridging veins were studied. These veins were stressed along their long axis and torn apart at various constant strainrates. The bridging vein's strain capacity was found to be dependent on strain rate, maximal strain was markedly reduced as the rate was increased. The maximal tension in the veins increases as the time to tearing decreases. The tearing tension was shown to be lower for bridging veins as compared to larger veins (femoral, popliteal, inferior vena cava).

High-speed films recorded from head on collision tests with cadavers have been analysed with respect to the angular acceleration and angular velocity which were evaluated with Smoothed Cubic-Spline Functions. These results compared with the autopsy findings in these cases and data from studies on angular acceleration to the head of squirrel monkeys carried out by Unterharnscheidt and Higgins indicate the bridging vein disruption due to rotational movement of the head is obtained when the angular acceleration exceeds 4500 rad/sec2 and/or the change in angular velocity exceeds 50 rad/sec. These tolerance levels are compared with data from collision experiments on living human beings.

The synthesis and homo- and copolymerization of new cyclic esters containing protected functional groups (hydroxyl, bishydroxyl, amino, and carboxyl) are described. Each of the e-caprolactone derivatives was generated by the Baeyer−Villiger oxidation of the corresponding cyclohexanone derivative. Monoprotection of 1,4-cyclohexanediol by benzylation or esterification was accomplished in moderate yields by reaction of benzyl bromide or 2,2‘-bis(phenyldioxymethyl)propionyl chloride. Each could be oxidized with pyridinium chlorochromate to yield the respective protected hydroxyl and bis(hydroxyl) functional cyclohexanones. The benzyl ether and benzyl ester protecting groups are readily removed by catalytic hydrogenolysis using Pd/C. Alternatively, ethyl-4-ketocyclohexylcarboxylate was hydrolyzed, and the free carboxylic acid was reesterified to the benzyl or tert-butyl 4-ketocyclohexylcarboxylate by esterification with either benzyl bromide or tert-butyl alcohol. These protecting groups were chosen because th...