The authorship dilemma: alphabetical or contribution?

Scientific communities have adopted different conventions for ordering authors on publications. Are these choices inconsequential, or do they have significant influence on individual authors, the quality of the projects completed, and research communities at large? What are the trade-offs of using one convention over another? In order to investigate these questions, we formulate a basic two-player game theoretic model, which already illustrates interesting phenomena that can occur in more realistic settings. We find that contribution-based ordering leads to a denser collaboration network and a greater number of publications, while alphabetical ordering can improve research quality. Contrary to the assumption that free riding is a weakness of the alphabetical ordering scheme, when there are only two authors, this phenomenon can occur under any contribution scheme, and the worst case occurs under contribution-based ordering. Finally, we show how authors working on multiple projects can cooperate to attain optimal research quality and eliminate free riding given either contribution scheme.     

A long-time presence of a foreign body in an episiotomy scar

OBJECTIVES: The object of our study was a long-time presence of a foreign body in an episiotomy scar. STUDY DESIGN: A case of 46-year old woman with a palpable tumour in a perineal region is described. RESULTS: This false tumour was caused by a surgical needle which was left in the body of the patient 19 years ago during the episiorrhaphy after the last labour. CONCLUSION: Because of a character and localisation of the change the method of choice was surgical treatment which completely eliminated all symptoms.     

Alveolar rhabdomyosarcoma of the uterine cervix

Porphyria cutanea tarda is characterized by severe connective tissue damage in sun-exposed skin. The regulated synthesis and degradation of the extracellular matrix by various matrix metalloproteinases (MMPs) determine its amount and composition within the skin. In this study, we therefore asked whether long-wave ultraviolet irradiation (340-450 nm) in conjunction with uroporphyrin I could modulate the synthesis of MMPs with substrate specificities for dermal (collagens I, III, V; proteoglycans) and basement membrane components (collagens IV, VII; fibronectin; laminin) and whether synthesis of the counteracting tissue inhibitor of metalloproteinases is also affected. After irradiation of uroporphyrin-pretreated fibroblasts, specific mRNAs of MMP-1 and MMP-3 increased concomitantly up to 2.7-fold compared with ultraviolet-irradiated cells and up to 10-fold compared with mock-irradiated or uroporphyrin I-treated controls. In contrast, mRNA levels of tissue inhibitor of metalloproteinases remained unaltered. Similar results were obtained by immunoprecipitation. Gelatin and casein zymography revealed increased proteolytic activity of MMP-2 and MMP-3 in blister fluids of patients with porphyria cutanea tarda, indicating that similar events may occur in vivo. Using deuterium oxide as enhancer and sodium azide as quencher of singlet oxygen, we could increase or reduce MMP synthesis, suggesting that singlet oxygen is the major intermediate in the upregulation of MMPs after irradiation of uroporphyrin-pretreated fibroblasts. Taken together, our results show that ultraviolet irradiation alone, and to a greater extent in conjunction with uroporphyrin I, results in an unbalanced synthesis of MMPs that may contribute to the destruction of the dermis and basement membrane, leading to blistering and accelerated photoaging in porphyria cutanea tarda patients.     

The analgesic potential of intraventricular polymer-encapsulated adrenal chromaffin cells in a rodent model of chronic neuropathic pain.

Adrenal chromaffin cells reportedly produce analgesic effects when implanted in the periaqueductal gray and the intrathecal space near the spinal cord. Chromaffin cells implanted in the cerebral ventricles may also produce analgesic effects, and the availability of the cerebral ventricles as a potential implant site could be advantageous for some patients. In fact, some of the first patients were implanted in the intraventricular site, even though the analgesic potential of that site had never been demonstrated. The present study was conducted to assess the analgesic potential of intraventricular, polymer-encapsulated calf adrenal chromaffin cells in the Bennett model. Sciatic nerve ligations produced substantial, long-lasting pain-related behaviors. However, there was no evidence that polymer-encapsulated adrenal chromaffin cells implanted in the cerebral ventricles produce analgesic effects in this model of chronic neuropathic pain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the design of filters for fourier and oSVD-based deconvolution in bolus tracking perfusion MRI

Object  

Bolus tracking perfusion evaluation relies on the deconvolution of a tracers concentration time-courses in an arterial and a tissue voxel following the tracer kinetic model. The object of this work is to propose a method to design a data-driven Tikhonov regularization filter in the Fourier domain and to compare it to the singular value decomposition (SVD)–based approaches using the mathematical equivalence of Fourier and circular SVD (oSVD).     

A case of a foreign body--surgical linen left in the abdominal cavity 25 years earlier

To confirm the biological effects of peptide growth factors on auditory neuron (AN) in vitro, the influence of NFG and bFGF on the survival status and the neurite regrowth of dissociated primary AN in postnatal chicks was studied with serum-free culture technique and cytologic quantitative method. The results demonstrated that the growth of non-neuron elements such as Schwann's cell was predominant in the earlier stage of culture. The neurite regrowth (bipolarity or unipolarity) of AN was observed at 24 hours after seeding. The growth rate increase during 48-72 hours in the surviving AN. These findings indicated that both growth factors exerted direct neuronotrophic effect on dissociated AN in vitro. NGF and bFGF acted in cooperation to promote the axon regeneration of AN. The concentration-dependent effect of NGF on neurite regrowth and neurone survival was found in the present study. The biological mechanism of NGF and bFGF on AN in vitro has been discussed.     

Modification of titanium surface with collagen and doxycycline as a new approach in dental implants

In this work, we investigate for the first time several issues involved in bio-adhesion process for a new type of chemically modified titanium surfaces (in their initial form and after collagen deposition), in order to assess their potential in dental implant surface modification. For this purpose, we studied the following: collagen adhesion, cytotoxicity, osteoblast cytomorphology, cell adhesion and proliferation, doxycycline embedding and modifications in the collagen film deposed on the metal surfaces, drug release from the collagen films. The improvement of adhesion between collagen film and titanium substrate, when hydroxyl and amino functional groups are assisting the surfaces was presented, all materials showing no cytotoxic effects as revealed by lactate dehydrogenase-based assay. The drug release from titanium–coll–doxy systems offers a dual mechanism of the delivery profile (burst release followed by moderate discharge of the antibiotic), with perspectives in soft tissue recovery postoperative stage.     

Thermomorphological analysis of Al2O3/HDPE nanocomposites: One approach in function of the processing and vinyltrimethoxysilane (VTMS) content

The present study assesses the influence of processing and adding alumina (Al₂O₃) nanoparticles functionalized with vinyltrimethoxysilane (VTMS) on high‐density polyethylene (HDPE) matrix. The model proposed by Henk, Kortsen, and Kvarts is used to calculate the ideal alumina nanoparticle concentration, in order to provide a larger interface area with lower agglomeration. Two different processing techniques are used to add the alumina nanoparticles functionalized with VTMS to the HDPE: direct blending and masterbatches applying the same processing extrusion parameters'. The alumina's nanoparticle functionalization with VTMS is confirmed by Fourier transform infrared spectroscopy analysis. The MFI is measured and nanoparticles dispersion is evaluated by scanning electron microscopy and by energy dispersive spectroscopy. Thermal behavior is measured by thermogravimetric analysis and differential scanning calorimetry. The addition of Al₂O₃ nanoparticles increases the thermal stability of the nanocomposites. Functionalization with VTMS provides improve adhesion to the polymer matrix, while the masterbatch processing technique promotes better alumina nanoparticle dispersion in the HDPE matrix and produce high crystalline composites. © 2019 Society of Plastics Engineers POLYM. ENG. SCI., 59:1332–1343 2019. © 2019 Society of Plastics Engineers     

Accumulation of the phytoalexin,glyceollin, in root nodules of soybean formed by effective and ineffective strains ofBradyrhizobium japonicum

Nitrogen fixation in root nodules formed by strain 2143 ofBradyrhizobium japonicum andGlycine max (L.) Merr. cv Williams 82 reaches a maximum at 21 to 28 days postinoculation and then begins to decline. The phytoalexin, glyceollin, accumulates in nodules coincident with the decline in nitrogen fixation. Nodules formed by strain 3122, which are unable to fix nitrogen, accumulate even higher levels of glyceollin and do so beginning 21 days postinoculation even though these nodules contain no recoverable bacteria. The typical phytoalexin response occurs within days of infection. The mechanism by which this response in theBradyrhizobium japonicum-soybean combination is delayed 2 to 3 weeks after infection is presently unknown but phytoalexin accumulation could contribute to the inability of the soybean-Bradyrhizobium japonicum combination to maintain high levels of nitrogen fixation throughout the growing season.     

Ectopic pregnancy in the stump of the uterine tube after in vitro fertilization

A rare case of ectopic pregnancy in stump of uterine tube after IVF, which was done after bilateral removal of uterine tubes, caused by uterine tube pregnancies was described. Diagnostic difficulties were shown in that case.