Charge dynamics in solar cells with a blend of π-conjugated polymer-fullerene studied by transient photo-generated voltage.

The biphasic feature of transient photo-generated voltage (TPV) is investigated in organic solar cells (OSCs) with a blend active layer of poly(3-hexylthiophene) (P3HT) and phenyl C61 butyric acid methyl ester (PCBM). The positive and negative components in biphasic TPV are explained through PCBM only and P3HT only devices. The negative and positive components are ascribed to the dipole formation at the buried interface of P3HT/indium tin oxide (ITO) and PCBM/ITO respectively. Based on these findings, two fundamental phenomena are revealed as follows: (1) interfacial modification on the buried interface inverts the negative component in biphasic TPV to a positive component, which prevents the leakage current channel in the conventional OSC structure; and (2) the solvent chosen transforms the positive component in biphasic TPV into a negative signal, which blocks the leakage current channel in the inverted OSC structure. Consequently, the study of TPV polarity provides the justification of the interaction at the buried interface. Besides, the decay of TPV is found to be bi-exponential, which can be used as a tool to estimate the degree of charge balance in OSCs.

Ingestion of isobutyl nitrite, a recreational chemical of abuse, causing fatal methemoglobinemia.

Isobutyl nitrite is widely abused as a sexual stimulant and enhancer of discotheque dancing. Though the usual route of administration by inhalation has not resulted in any toxicologically verified deaths, there may be fatal toxic methemoglobinemia if the chemical is orally ingested. A second case of death following ingestion is discussed.

Pattern of intersecting fractures and direction of fire.

In gunshot wounds of the skull, the pattern of intersecting fractures may be used to verify the direction of fire. It may be the only indicator of direction, if overlying skin is destroyed or inconclusive and if bevelling is absent in gunshot defects of thin temporal bone.

Determination of direction of fire from graze gunshot wounds of internal organs.

Graze gunshot wounds of internal organs produce injuries similar to those seen on the skin surface. Careful examination of the distribution of lacerations on the tissue tags along the margins of the graze trough may permit a determination of the direction of fire.

Exit keyhole lesion and direction of fire in a gunshot wound of the skull.

An exit keyhole lesion of the skull is presented. A defect with keyhole configuration has been previously described only at the site of entrance. This case documents that such a lesion should not be interpreted as an indicator of entrance in all cases.

Rib spreader laceration: a confusing artifact of emergency thoracotomy.

During emergency thoracotomy, an artifactual injury complex consisting of laceration, abrasion, and, rarely, contusion may be formed by application of a surgical instrument called a rib spreader. Six cases demonstrating this confusing injury are presented, and its formation is discussed.

Fatal methemoglobinemia resulting from ingestion of isobutyl nitrite, a "room odorizer" widely used for recreational purposes.

The alkyl nitrites, specifically isobutyl nitrite, have taken a prominent place among those substances enjoying widespread recreational use, primarily in discotheques and in any toxicologically verified deaths, the chemical may cause fatal toxic methemoglobinemia if ingested. A case with a fatal outcome is presented, and the chemistry and toxicology of the substance are discussed.

"Foreshoring": characteristics of shored entry wounds and corresponding wounds with shoring material as an intermediate target.

Just as an exit wound can be shored by firm material pressed against the skin, so can an entry wound. The configuration of supported entrance wounds is examined in relation to type of shoring material and weapon caliber, by using anesthetized pigs. Corresponding wounds with the same shoring materials used as intermediate targets are also studied.

Determination of direction of fire from graze gunshot wounds.

Careful examination of experimentally produced graze bullet wounds of skin demonstrates that specific wound characteristics may be useful in determining the direction in which the projectile traversed the skin surface. These principles are applied to actual cases with known circumstances.

Role of arteriography in rectal hemorrhage due to arteriovenous malformations and diverticulosis.

Nine patients with arteriographic right colon arteriovenous malformations (AVM's) are reviewed. Even though five of the eight surviving patients had diverticulosis in remaining colon, right colectomy with removal of the AVM effectively controlled bleeding in seven of the eight patients in follow-up intervals of 14-66 months. Such results suggest that right colon AVM, rather than diverticulosis, may be the more common cause of chronic recurrent lower intestinal hemorrhage in the elderly. Rebleeding occurred in one patient and has heretofore been reported in seven cases. However, since AVM bleeding is rarely life-threatening, right colectomy for chronic recurrent rectal bleeding is justifiable as the initial operative procedure for an AVM, even in the presence of left colon or sigmoid diverticulosis. In the same five year period, 1973-1977, four additional patients with massive hemorrhage, characteristic of diverticulosis, had emergency arteriography with demonstration of a localized site of diverticular bleeding that was controllable by partial colon resection. Consequently, segmental resection of the colon, utilizing selective arteriography, has thus far eliminated bleeding in eight of nine patients with diverticulosis. The judicious use of arteriography in patients with diverticulosis and rectal bleeding substantially reduces the requirement for subtotal colectomy and ileoproctostomy.