Guidance, flight mechanics and trajectory optimization. Volume 14 - Entry guidance equations

Entry guidance equations, reference trajectories, and guidance system mechanizatio

Guidance, flight mechanics and trajectory optimization. Volume 1 - Coordinate systems and time measure

Coordinate measuring system for flight control, and trajectory optimizatio

Dye-sensitized photooxidation as a tool for determining the degree of exposure of amino acid residues in proteins. The methionyl residues in ribonuclease A.

Abstract Optical rotation measurements and absorption difference spectroscopy of ribonuclease A in different water-acetic acid mixtures showed that at least three conformational situations exist for the protein molecule at different levels of acetic acid concentration. Hematoporphyrin-sensitized photooxidation of the native as well as of the denatured proteins allowed us to detect three discrete states of reactivity for the 4 methionyl residues of ribonuclease A. On the basis of the photooxidation kinetics and of the conformational analyses, we concluded that methionine-29 is partly exposed in the native protein and methionine-13 is partially buried, whereas methionine-30 and methionine-79 are deeply buried. The importance of the single methionyl residues for the catalytic activity of the enzyme has been also resolved. The described procedure appears to be a reliable tool for examining the state of the amino acid residues in proteins

Site-directed spin labeling of the mitochondrial membrane. Synthesis and utilization of the adenosine triphosphatase inhibitor (N-(2, 2, 6, 6-tetramethyl-piperidyl-1-oxyl)-N'-(cyclohexyl)-carbodiimide).

Abstract NCCD (N-(2,2,6,6-tetramethyl-piperidyl-1-oxyl)-N'-(cyclohexyl)carbodiimide) is a spin label inhibitor of ATPase of mitochondrial membrane fragments. Upon binding (∼0.5 nmole per mg of protein) its electron paramagnetic resonance spectrum becomes highly immobilized (τc = 2.10-8 s). The bound but not the free label is reduced by succinate, indicating that electrons can be transferred from the respiratory chain to the ATPase system. The Mn++ATP complex decreases the paramagnetic signal of NCCD bound to membrane fragments about 30%. Such an interaction can be the consequence of the vicinity of the binding sites of the two species

Surgical repair of Achilles tendon rupture in dogs: A review of the literature, a case report and new perspectives

Achilles tendon rupture in the dog is a common traumatic lesion. An accurate evaluation of etiology, grade of the lesion with or without loss of tendon substance, and time elapsed from the trauma can guide the surgeon in choosing the best surgical technique. Moreover, the healing process after a tendon injury is usually difficult and uncertain because the prognosis is influenced by extent of trauma, time elapsed between the trauma and its treatment and low tendon vascularization. However, the rapid development of tissue engineering and regenerative medicine could soon result in the development of scaffolds with bioactive proteins that can direct the healing process toward complete tendon regeneration without fibrotic tissue development

Non-pharmaceutical Interventions and the Infodemic on Twitter: Lessons Learned from Italy during the Covid-19 Pandemic

The COVID-19 pandemic changed expectations for information dissemination and use around the globe, challenging accepted models of communications, leadership, and social systems. We explore how social media discourse about COVID-19 in Italy was affected by the rapid spread of the virus, and how themes in postings changed with the adoption of social distancing measures and non-pharmaceutical interventions (NPI). We used topic modeling and social network analysis to highlight critical dimensions of conversations around COVID-19: 1) topics in social media postings about the Coronavirus; 2) the scope and reach of social networks; and 3) changes in social media content as the nation moved from partial to full social distancing. Twitter messages sent in Italy between February 11th and March 10th, 2020. 74,306 Tweets sent by institutions, news sources, elected officials, scientists and social media influencers. Messages were retweeted more than 1.2 million times globally. Non-parametric chi-square statistic with residual analysis to identify categories, chi-square test for linear trend, and Social Network Graphing. The first phase of the pandemic was dominated by social media influencers, followed by a focus on the economic consequences of the virus and placing blame on immigrants. As the crisis deepened, science-based themes began to predominate, with a focus on reducing the spread of the virus through physical distancing and business closures Our findings highlight the importance of messaging in social media in gaining the public’s trust and engagement during a pandemic. This requires credible scientific voices to garner public support for effective mitigation. Fighting the spread of an infectious disease goes hand in hand with stemming the dissemination of lies, bad science, and misdirection

Evaluation of the Iatrogenic Sciatic Nerve Injury following Double Pelvic Osteotomy Performed with Piezoelectric Cutting Tool in Dogs

(1) Background: The double pelvic osteotomy (DPO) is a prophylactic surgical procedure associated with 0.4% incidence of sciatic nerve injury. The piezoelectric cutting tool is a surgical device able to involve only mineralized tissue avoiding neurovascular tissue and other soft tissue. This study aimed to evaluate the sciatic nerve injury observed in dogs underwent iliac osteotomy performed using the piezoelectric cutting tool. (2) Methods: Dogs underwent DPO performed with piezoelectric cutting tool were included. Neurological assessment was performed 6 and 24 h after surgery and then repeated 12 days, 4 and 8 weeks after surgery. Temporary and or permanent sciatic nerve injury were recorded. (3) Results: 84 DPOs performed in fifty dogs were included. No temporary/permanent neurological disease associated with iatrogenic damage of the sciatic nerve were observed. (4) Conclusions: The iliac osteotomy performed with piezoelectric cutting tool was not associated to iatrogenic sciatic nerve injury

Use of Transversus Abdominis Plane and Intercostal Blocks in Bitches Undergoing Laparoscopic Ovariectomy: A Randomized Controlled Trial

In humans and dogs, loco-regional anesthesia is associated with lower peri-operative opioid consumption and less related side effects. The combination of transversus abdominis plane (TAP) and intercostal blocks can be used to desensitize the entire abdominal wall in dogs. The aim of this study was to evaluate the effectiveness of TAP and intercostal blocks in bitches undergoing laparoscopic ovariectomy. Twenty client-owned bitches were enrolled in this double-blinded randomized controlled trial. After premedication with dexmedetomidine, methadone and ketamine, the animals were randomized into two groups. Dogs in the TAP group received intercostal blocks from T8 to T10 and a TAP block with ropivacaine. Dogs in the FEN group received a fentanyl bolus and a constant rate infusion for the entire duration of the procedure. Intra-operative cardiovascular stability, post-operative pain scores, rescue opioid requirement, dysphoria during recovery, time to attain sternal recumbency and interest in food at 6 h post-extubation were compared. Bitches in the TAP group received a statistically significant lower amount of rescue fentanyl intra-operatively and methadone post-operatively. Pain scores were lower in the TAP group until 6 h post-extubation. No difference was found for dysphoric recoveries, time to attain sternal recumbency and appetite at 6 h post-extubation. No adverse event was recorded for any of the dogs. The combination of TAP and intercostal blocks can be part of an effective multi-modal analgesic strategy in bitches undergoing laparoscopic ovariectomy

Lymphatic drainage mapping with indirect lymphography for canine mammary tumors

Mammary gland tumors are the most common canine neoplasms. They account for 25– 50% of all tumors diagnosed in bitches. Metastases and recurrences develop in about 35–70% of bitches following excision. The presence of regional lymph node metastases is a relevant factor affecting prognosis and treatment in cases of mammary gland tumors. The sentinel lymph node (SLN) is the first lymph node (or nodes) in the regional lymphatic basin that receives lymphatic flow from the primary neoplasm. The aim of this study is to investigate the SLN with indirect lymphography for a mammary tumor in dogs. The knowledge of the precise drainage pattern and SLN of the neoplastic mammary glands would provide clinically relevant information to the surgeon and to the oncologist, and it would be of high importance for the surgeon not only for performing the most adequate surgical excision but also for determining an accurate post-surgical prognosis