Introduction: Chitin is a biopolymer that forms the exoskeleton of arthropods, and is found in the cell walls of fungi. It has a wide range of uses in fields such as cosmetics, pharmacy, medicine, bioengineering, agriculture, textiles and environmental engineering based upon its nontoxic, ecofriendly, biocompability and biodegradability characteristics. Commercially, chitin is obtained from processing the outer skeleton of Crustacea such as shrimp, crab, prawn and crayfish after they have been consumed as food. The study aims to examine the nature of bat guano and to determine if it is a practical source of chitin, which has not been done previously.Results: In this study, the chitin content of dry bat guano samples was found to be 28%. The bat guano, which was collected from Karacamal Cave, came from the bat species Rhinolophus hipposideros. The chitosan yield of this chitin was 79%. The chitin produced from the bat guano was determined to be in the alpha form according to Fourier transform infrared spectroscopy (FTIR) results. The crystallinity of the chitin and chitosan samples was calculated as 85.49 and 58.51% respectively by X-ray crystallography (XRD) experiments. According to scanning electron microscope (SEM) micrographs, the chitin and chitosan structures were shaped like nanofibers. The thermogravimetric analysis (TGA) results showed that both chitin and chitosan had two step weight losses, which are characteristic of these materials. The nitrogen content of the chitin and chitosan was 6.47 and 7.3% respectively according to the elemental analysis results. Conclusions:In this research, it has been observed that bat guano can be considered to be an alternative source of chitin and chitosan to crab, shrimp, crayfish and krill.

Abstract. Various experimental methods (XRD, FTIR, SAXS, DLS and SEM) were used to investigate structures of the silk samples weaved by spiders in Turkey. Silk samples were collected from the natural habitats belonging to the spider species (i.e., Near Salt Lake/Şereflikoçhisar,İvriz Dam/Eregli-Konya, Karataş Lake/Burdur and several locations in Black Sea Region of Turkey). Among all collected species, Araneidae (Araneus angulatus, Argiope bruennichi, Argiope lobata, Larinoides cornutus), Eresidae (Eresus cinnaberinus), Agelenidae (Agelena labyrinthica), Oecobidae (Uroctea durandi), Miturgidae (Cheiracanthium erraticum), Salticidae (Heliophanus flavipes, Philaeus chrysops), Theridiidae (Steatoda paykulliana) and Gnaphosidae were found significant amongst other spider species. Structural differences and similarities of these species were reported. Diameter range of draglines, inter crystallite distance of nano-size structures, mean size range of nano-structure aggregations, crystallite size range, information about protein content were obtained. The mechanical properties of some silk fibers were also investigated.

Introduction: Chitin is a biopolymer that forms the exoskeleton of arthropods, and is found in the cell walls of fungi. It has a wide range of uses in fields such as cosmetics, pharmacy, medicine, bioengineering, agriculture, textiles and environmental engineering based upon its nontoxic, ecofriendly, biocompability and biodegradability characteristics. Commercially, chitin is obtained from processing the outer skeleton of Crustacea such as shrimp, crab, prawn and crayfish after they have been consumed as food. The study aims to examine the nature of bat guano and to determine if it is a practical source of chitin, which has not been done previously.Results: In this study, the chitin content of dry bat guano samples was found to be 28%. The bat guano, which was collected from Karacamal Cave, came from the bat species Rhinolophus hipposideros. The chitosan yield of this chitin was 79%. The chitin produced from the bat guano was determined to be in the alpha form according to Fourier transform infrared spectroscopy (FTIR) results. The crystallinity of the chitin and chitosan samples was calculated as 85.49 and 58.51% respectively by X-ray crystallography (XRD) experiments. According to scanning electron microscope (SEM) micrographs, the chitin and chitosan structures were shaped like nanofibers. The thermogravimetric analysis (TGA) results showed that both chitin and chitosan had two step weight losses, which are characteristic of these materials. The nitrogen content of the chitin and chitosan was 6.47 and 7.3% respectively according to the elemental analysis results. Conclusions:In this research, it has been observed that bat guano can be considered to be an alternative source of chitin and chitosan to crab, shrimp, crayfish and krill.

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Introduction: Black widow spider bites cause severe poisoning (latrodectism) with symptoms such as muscle spasm, rigidity, pain, vomiting, hypertension, and tachycardia. Although Latrodectus mactans (L. mactans) is the most well-known species to cause latrodectism, it has not been reported in Turkey. We report a poisoning case caused by Latrodectus tredecimguttatus (L. tredecimguttatus) spider a species known to be in Turkey for the first time in the literature.Case: A 35-year-old male patient presented with complaints of pain in the lower extremities and excessive sweating due to a spider bite. Discomfort, agitation, a sweaty appearance, tachycardia, and hypertensive attack were observed in the patient. Because black widow antivenom is not available in Turkey and because of the continuation of symptoms despite treatment for 12 hours in the emergency department, the patient was transferred to the intensive care unit, where he was given IV sedoanalgesia. Nicardipine infusion was administered to treat hypertension attack. The patient's symptoms improved on the fifth day. The dead spider that was brought in was identified by an expert biologist as L. tredecimguttatus. Conclusion:It should be considered that latrodectism due to L. tredecimguttatus spider bite may be resistant to emergent treatment and hospitalization may be required.

A spider can produce several types of silk (dragline, cocoon, etc.) which is a composite material with a hierarchical structure. This structure includes beta-sheet, polypeptide chain network and silk fibril. If the design of these bio-based materials and the relationships between protein sequence and structure-property are understandable, this knowledge can be used in technological applications ranging from medical (micro-sutures, artificial ligaments, tendons, and drug delivery coatings) to military (body armor, light weight gear) to civilian (textiles) usages [1][2][3]. The purpose of this study is to characterize the structure of silk cocoon samples which have high crystalinity and valuable protein contents. X-ray powder diffraction and SWAXS (Small and Wide Angle X-ray Scattering) methods were used for the structural characterizations. ARANEIDAE (Simon, 1895) and GNAPHOSIDAE (Pocock, 1898) families have been especially studied because of their productive properties. The crystallite size range, crystallinity percentages, number of crystallites and the distances between crystallites (depending on the direction of fibrils) have been determined. The results have been systematically evaluated and recorded as database for our ongoing TBAG project [4]. Especially in nanotechnological investigations, their superior performance under different conditions and water repellent properties attracts much attention [1][2][3][4][5]. In this study, Small and Wide Angle X-ray Scattering (SAXS and WAXS) methods were used to characterize the natural structures of poplar (populus), hornbeam (carpinus), chesnut (castanea) and walnut (juglans) trees originally form Turkey forests and their micropowders of aspen heartwood and aspen sapwood parts. After first structural comparisons , their micropowder forms, metal oxide nanopowders (aluminium, cobalt, nickel oxide etc., size range ~ 10-20 nm) and kleiberit 303 (as PVAC base adhesive) were mixed and the new substances were typically stirred for 30 min-120 min to prepare cylindirical and planar shaped nanocomposite hardboards. As secondary part of the study, SWAXS measurements have been performed for wood nanocomposites to determine the shape and distributions of nanosized aggregation. Pair distance distributions and size distributions were obtained and compared to prepare homogenous samples. Beside of these studies, moisture contents, thickness swelling of the samples and mechanical properties (strain and stress) were also determined. Acknowledgement: Authors thank Hacettepe Univ. Scientific Research Unit for the support in the project no: 06A602012

Microsymposia crystallography. Recently, an interest has grown for protein powder diffraction which is becoming a well-established method in the field of structure refinement and molecular replacement. With the use of two examples it is shown that de novo solutions to the phase problem can be obtained at low resolution via phasing methods such as the isomorphous replacement method. Using synchrotron radiation, high quality protein powder patterns have been collected in which pHand radiation-induced anisotropic lattice changes were exploited in order to reduce the challenging and powder specific problem of overlapping reflections. The Single Isomorphous Replacement method enabled the computation of molecular envelopes and the mapping out of the solvent channels in the crystal. Electron density maps in which features of the secondary structure of the lysozyme protein molecule can be discerned, were then obtained using the Multiple Isomorphous Replacement method (as illustrated in the image).