| 51. |
- Berggren, Elin, et al.
(författare)
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Charge Transfer in the P(g42T-T) : BBL Organic Polymer Heterojunction Measured with Core-Hole Clock Spectroscopy
- 2023
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 127:49, s. 23733-23742
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Tidskriftsartikel (refereegranskat)abstract
- The conductivity of organic polymer heterojunction devices relies on the electron dynamics occurring along interfaces between the acceptor and donor moieties. To investigate these dynamics with chemical specificity, spectroscopic techniques are employed to obtain localized snapshots of the electron behavior at selected interfaces. In this study, charge transfer in blends (by weight 10, 50, 90, and 100%) of p-type polymer P(g(4)2T-T) (bithiophene-thiophene) and n-type polymer BBL (poly(benzimidazo-benzo-phenanthroline)) was measured by resonant Auger spectroscopy. Electron spectra emanating from the decay of core-excited states created upon X-ray absorption in the donor polymer P(g(4)2T-T) were measured in the sulfur KL2,3L2,3 Auger kinetic energy region as a function of the excitation energy. By tuning the photon energy across the sulfur K-absorption edge, it is possible to differentiate between decay paths in which the core-excited electron remained on the atom with the core-hole and those where it tunneled away. Analyzing the competing decay modes of these localized and delocalized (charge-transfer) processes facilitated the computation of charge-transfer times as a function of excitation energy using the core-hole clock method. The electron delocalization times derived from the measurements were found to be in the as/fs regime for all polymer blends, with the fastest charge transfer occurring in the sample with an equal amount of donor and acceptor polymer. These findings highlight the significance of core-hole clock spectroscopy as a chemically specific tool for examining the local charge tunneling propensity, which is fundamental to understanding macroscopic conductivity. Additionally, the X-ray absorption spectra near the sulfur K-edge in the P(g(4)2T-T) polymer for different polymer blends were analyzed to compare molecular structure, orientation, and ordering in the polymer heterojunctions. The 50% donor sample exhibited the most pronounced angular dependence of absorption, indicating a higher level of ordering compared to the other weight blends. Our studies on the electron dynamics of this type of all-polymer donor-acceptor systems, in which spontaneous ground-state electron transfer occurs, provide us with critical insights to further advance the next generation of organic conductors with mixed electron-hole conduction characteristics suitable for highly stable electrodes of relevance for electronic, electrochemical, and optoelectronic applications.
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| 52. |
- Bergqvist, D, et al.
(författare)
-
Abdominal injury from sporting activities
- 1982
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Ingår i: British journal of sports medicine. - : BMJ. - 1473-0480 .- 0306-3674. ; 16:2, s. 76-79
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Tidskriftsartikel (refereegranskat)abstract
- The frequency of abdominal injury is rising. In an analysis of 1,354 cases of closed abdominal trauma sustained during a 30-year period (1950-1979) in Skaraborg County, Sweden, a distinct increase was found in the numbers associated with sporting activities. The severity of the injuries caused by sports likewise showed an increase. The representation of injured organs was of the same order as in the total series of closed abdominal injuries. An analysis of the 136 cases of sports-associated injury is presented with regard to cause and type of the injuries, diagnosis and prognosis.
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| 53. |
- Bergqvist, D, et al.
(författare)
-
Abdominal trauma in persons older than 60 years
- 1982
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Ingår i: Acta Chirurgica Scandinavica. - 0001-5482. ; 148:7, s. 569-573
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Tidskriftsartikel (refereegranskat)abstract
- Abdominal trauma occurring in persons older than 60 years over a 30-year period (1950-79) in a well defined region of Sweden was reviewed. The 177 patients comprised 12.5% of the total with abdominal trauma during that period. Road traffic accidents were the main cause of trauma (48% of cases). The incidence of motor-car accidents rose sharply during the first two decades of the study. Injuries to the liver and bile ducts and multiple intra-abdominal injuries were more common in the elderly than in younger patients, but injury to the abdominal wall was less common. A tendency towards more severe injuries and multiple trauma with extra-abdominal involvement emerged during the study period. The mortality rate was 27.6% in the patients older than 60, but 9.1% in the overall patient series with abdominal trauma. One-third of all the deaths among the older patients were directly due to the abdominal trauma. One consequence of the increasing numbers of old people in the general population is probably that more and more cases of abdominal trauma will be seen in the higher age groups.
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| 54. |
- Bergqvist, D, et al.
(författare)
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Blunt renal trauma. Analysis of 417 patients
- 1983
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Ingår i: European Urology. - 1873-7560. ; 9:1, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- Case records of 417 patients, from a well-defined area, who were hospitalized because of blunt renal trauma during the period 1950-1979 were analyzed. The incidence increased during the final decade, corresponding to a rising incidence of motor traffic accidents and sports injuries. Young patients, between 10 and 29 years of age, were responsible for the increase and half of all patients were in this age group. Associated injuries were frequent. Emergency urography was rare during the earlier part of the investigation period, but the frequency increased strongly thereafter. Treatment was mainly conservative (nonoperative) except in patients with major renal injuries. Nephrectomy was performed in 22 patients. Reconstructive surgery was performed especially in patients with intermediate renal injuries during the final decade. The total mortality was 6.5%. Only 7 patients (1.7%) died from the renal injury. A dramatic reduction in the hospitalization time was noted.
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| 55. |
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| 56. |
- Bergqvist, D, et al.
(författare)
-
Intestinal trauma, Analysis of 101 cases
- 1981
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Ingår i: Acta Chirurgica Scandinavica. - 0001-5482. ; 147:8, s. 629-635
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Tidskriftsartikel (refereegranskat)abstract
- Intestinal injuries sustained by 101 Swedish patients during the period 1950-1979 are reviewed. The abdominal trauma was blunt in 78 cases and penetrating in 23. Small-bowel and mesenteric, but not large-bowel, injuries showed increasing frequency. This was associated with rising numbers of motorcar accidents. Injuries to other abdominal organs were found in 56 of the 101 patients, particularly in those with mesenteric or large-bowel trauma. Clear physical signs of intra-abdominal injury led to rapid surgical exploration in most cases, but some operations were performed after relatively long observation. Most injuries, including those in the colon, were treated with primary repair or resection. Decompressive colostomy or exteriorization were rarely performed. Deaths were mainly caused by other factors than the type of operation. The mortality rate (35%) was constant.
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| 57. |
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| 58. |
- Bergqvist, D, et al.
(författare)
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Low molecular weight heparin for thromboprophylaxis and epidural/spinal anaesthesia--is there a risk?
- 1992
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Ingår i: Acta Anaesthesiologica Scandinavica. - 0001-5172. ; 36:7, s. 605-609
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Tidskriftsartikel (refereegranskat)abstract
- This article reviews the problem of bleeding in connection with epidural/spinal anaesthesia, with special emphasis on the use of low molecular weight heparins for thromboprophylaxis. There are methodological difficulties to studying the problem in a scientifically correct way because of the rarity of the complication. However, from the data in the literature there are no indications of an increased risk in using the combination of low molecular weight heparin in prophylactic doses and epidural/spinal anaesthesia. So far, there is only a single case report, of spinal haematoma, although low molecular weight heparins have been used in combination with epidural/spinal anaesthesia in at least 1,000,000 patients. In controlled studies, at least 10,000 patients have been given the combination without complications.
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| 59. |
- Bergqvist, D, et al.
(författare)
-
Patients with abdominal trauma and fatal outcome: analysis of a 30-year series
- 1983
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Ingår i: Journal of Trauma. - 0022-5282. ; 23:6, s. 499-502
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Tidskriftsartikel (refereegranskat)abstract
- Patients with blunt abdominal trauma and fatal outcome during 30 years in a well-defined rural Swedish area have been analyzed. There were 127 patients. Several facts indicate that more severe trauma has been appearing more often during this period The mortality rate has, however, been stable, but the patients have become older. More patients die from pulmonary complications than from the trauma itself. One very important development is the significant decrease in mortality among children.
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| 60. |
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