scholarly journals Generalized Stoichiometry and Biogeochemistry for Astrobiological Applications

2021 ◽  
Vol 83 (7) ◽  
Author(s):  
Christopher P. Kempes ◽  
Michael J. Follows ◽  
Hillary Smith ◽  
Heather Graham ◽  
Christopher H. House ◽  
...  
Keyword(s):  
The Body ◽  
Cell Physiology ◽  
Theoretical Treatment ◽  
Physiological Models ◽  
Elemental Ratios ◽  
Chemical Systems ◽  
Classic Work ◽  
Planetary Missions ◽  
Key Questions

AbstractA central need in the field of astrobiology is generalized perspectives on life that make it possible to differentiate abiotic and biotic chemical systems McKay (2008). A key component of many past and future astrobiological measurements is the elemental ratio of various samples. Classic work on Earth’s oceans has shown that life displays a striking regularity in the ratio of elements as originally characterized by Redfield (Redfield 1958; Geider and La Roche 2002; Eighty years of Redfield 2014). The body of work since the original observations has connected this ratio with basic ecological dynamics and cell physiology, while also documenting the range of elemental ratios found in a variety of environments. Several key questions remain in considering how to best apply this knowledge to astrobiological contexts: How can the observed variation of the elemental ratios be more formally systematized using basic biological physiology and ecological or environmental dynamics? How can these elemental ratios be generalized beyond the life that we have observed on our own planet? Here, we expand recently developed generalized physiological models (Kempes et al. 2012, 2016, 2017, 2019) to create a simple framework for predicting the variation of elemental ratios found in various environments. We then discuss further generalizing the physiology for astrobiological applications. Much of our theoretical treatment is designed for in situ measurements applicable to future planetary missions. We imagine scenarios where three measurements can be made—particle/cell sizes, particle/cell stoichiometry, and fluid or environmental stoichiometry—and develop our theory in connection with these often deployed measurements.

Scaffolds for Drug Delivery in Tissue Engineering

2008 ◽  
Vol 1 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Vikas V. Gaikwad ◽  
Abasaheb B. Patil ◽  
Madhuri V. Gaikwad
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Heart Diseases ◽  
Cartilage Regeneration ◽  
Tissue Growth ◽  
The Body ◽  
Patient Specific ◽  
In Situ Gel ◽  
Heart Muscle Cells

Scaffolds are used for drug delivery in tissue engineering as this system is a highly porous structure to allow tissue growth.  Although several tissues in the body can regenerate, other tissue such as heart muscles and nerves lack regeneration in adults. However, these can be regenerated by supplying the cells generated using tissue engineering from outside. For instance, in many heart diseases, there is need for heart valve transplantation and unfortunately, within 10 years of initial valve replacement, 50–60% of patients will experience prosthesis associated problems requiring reoperation. This could be avoided by transplantation of heart muscle cells that can regenerate. Delivery of these cells to the respective tissues is not an easy task and this could be done with the help of scaffolds. In situ gel forming scaffolds can also be used for the bone and cartilage regeneration. They can be injected anywhere and can take the shape of a tissue defect, avoiding the need for patient specific scaffold prefabrication and they also have other advantages. Scaffolds are prepared by biodegradable material that result in minimal immune and inflammatory response. Some of the very important issues regarding scaffolds as drug delivery systems is reviewed in this article.

scholarly journals Ferromagnetic soft catheter robots for minimally invasive bioprinting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cheng Zhou ◽  
Youzhou Yang ◽  
Jiaxin Wang ◽  
Qingyang Wu ◽  
Zhuozhi Gu ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
The Body ◽  
Magnetic Actuation ◽  
Internal Organs ◽  
Planar Surfaces ◽  
Reinforced Polymer ◽  
Direct Fabrication ◽  
Digitally Controlled

AbstractIn vivo bioprinting has recently emerged as a direct fabrication technique to create artificial tissues and medical devices on target sites within the body, enabling advanced clinical strategies. However, existing in vivo bioprinting methods are often limited to applications near the skin or require open surgery for printing on internal organs. Here, we report a ferromagnetic soft catheter robot (FSCR) system capable of in situ computer-controlled bioprinting in a minimally invasive manner based on magnetic actuation. The FSCR is designed by dispersing ferromagnetic particles in a fiber-reinforced polymer matrix. This design results in stable ink extrusion and allows for printing various materials with different rheological properties and functionalities. A superimposed magnetic field drives the FSCR to achieve digitally controlled printing with high accuracy. We demonstrate printing multiple patterns on planar surfaces, and considering the non-planar surface of natural organs, we then develop an in situ printing strategy for curved surfaces and demonstrate minimally invasive in vivo bioprinting of hydrogels in a rat model. Our catheter robot will permit intelligent and minimally invasive bio-fabrication.

Mammary-type Myofibroblastoma with Leiomyomatous Differentiation: A Rare Variant with Potential Pitfalls

2021 ◽  
pp. 106689692110313
Author(s):  
Alexander M. Strait ◽  
Julia A. Bridge ◽  
Anthony J. Iafrate ◽  
Marilyn M. Li ◽  
Feng Xu ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Transcriptome Sequencing ◽  
Smooth Muscle Actin ◽  
The Body ◽  
Muscle Actin ◽  
Mature Adipose Tissue ◽  
Spindle Cells ◽  
Whole Transcriptome Sequencing ◽  
Whole Transcriptome

Myofibroblastoma is a rare, benign stromal tumor with a diverse morphologic spectrum. Mammary-type myofibroblastoma (MTMF) is the extra-mammary counterpart of this neoplasm and its occurrence throughout the body has become increasingly recognized. Similar morphologic variations of MTMF have now been described which mirror those seen in the breast. We describe a case of intra-abdominal MTMF composed of short fascicles of eosinophilic spindle cells admixed with mature adipose tissue. The spindle cells stained diffusely positive for CD34, desmin, smooth muscle actin, and h-caldesmon by immunohistochemistry. Concurrent loss of RB1 (13q14) and 13q34 loci were confirmed by fluorescence in situ hybridization whereas anchored multiplex PCR and whole transcriptome sequencing did not reveal any pathognomonic fusions suggesting an alternative diagnosis. To the best of our knowledge this is the first documented case of leiomyomatous variant of MTMF.

Tumor Microenvironment-Triggered In-Situ Cancer Vaccines with Dual Immunogenic Cell Death Inductions for Elevated Antitumor and Antimetastatic Therapy

Nanoscale ◽  
2021 ◽  
Author(s):  
Jun Lin ◽  
Binbin Ding ◽  
Pan Zheng ◽  
Dong Li ◽  
Meifang Wang ◽  
...  
Keyword(s):  
Cell Death ◽  
Tumor Microenvironment ◽  
Immune Responses ◽  
Cancer Immunotherapy ◽  
Cancer Vaccines ◽  
High Specificity ◽  
The Body ◽  
Immunogenic Cell Death ◽  
Specific Antigens

Cancer vaccine is to make tumor-specific antigens into vaccines, which then are injected back into the body to activate immune responses for cancer immunotherapy. Despite the high specificity and therapeutic...

Expression of a novel FGF in the Xenopus embryo. A new candidate inducing factor for mesoderm formation and anteroposterior specification

Development ◽  
1992 ◽  
Vol 114 (3) ◽  
pp. 711-720 ◽  
Author(s):  
H.V. Isaacs ◽  
D. Tannahill ◽  
J.M. Slack
Keyword(s):  
Specific Activity ◽  
Biological Properties ◽  
The Body ◽  
Mesoderm Induction ◽  
Gastrula Stage ◽  
Blastula Stage ◽  
Mesoderm Formation ◽  
Low Levels

We have cloned and sequenced a new member of the fibroblast growth factor family from Xenopus laevis embryo cDNA. It is most closely related to both mammalian kFGF (FGF-4) and FGF-6 but as it is not clear whether it is a true homologue of either of these genes we provisionally refer to it as XeFGF (Xenopus embryonic FGF). Two sequences were obtained, differing by 11% in derived amino acid sequence, which probably represent pseudotetraploid variants. Both the sequence and the behaviour of in vitro translated protein indicates that, unlike bFGF (FGF-2), XeFGF is a secreted molecule. Recombinant XeFGF protein has mesoderm-inducing activity with a specific activity similar to bFGF. XeFGF mRNA is expressed maternally and zygotically with a peak during the gastrula stage. Both probe protection and in situ hybridization showed that the zygotic expression is concentrated in the posterior of the body axis and later in the tailbud. Later domains of expression were found near the midbrain/hindbrain boundary and at low levels in the myotomes. Because of its biological properties and expression pattern, XeFGF is a good candidate for an inducing factor with possible roles both in mesoderm induction at the blastula stage and in the formation of the anteroposterior axis at the gastrula stage.

scholarly journals Towards feedback-controlled nanomedicines for smart, adaptive delivery

2018 ◽  
Vol 244 (4) ◽  
pp. 283-293 ◽  
Author(s):  
Stephen J. Jones ◽  
Annette F. Taylor ◽  
Paul A Beales
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
The Body ◽  
Living Systems ◽  
Prolonged Release ◽  
Drug Bioavailability ◽  
Drug Release Profile ◽  
Chemical Systems

Nanomedicines for controlled drug release provide temporal and spatial regulation of drug bioavailability in the body. The timing of drug release is usually engineered either for slow gradual release over an extended period of time or for rapid release triggered by a specific change in its physicochemical environment. However, between these two extremes, there is the desirable possibility of adaptive nanomedicines that dynamically modulate drug release in tune with its changing environment. Adaptation and response through communication with its environment is a fundamental trait of living systems; therefore, the design of biomimetic nanomedicines through the approaches of bottom-up synthetic biology provides a viable route to this goal. This could enable drug delivery systems to optimize release in synchronicity with the body’s natural biological rhythms and the personalized physiological characteristics of the patient, e.g. their metabolic rate. Living systems achieve this responsiveness through feedback-controlled biochemical processes that regulate their functional outputs. Towards this goal of adaptive drug delivery systems, we review the general benefits of nanomedicine formulations, provide existing examples of experimental nanomedicines that encapsulate the metabolic function of enzymes, and give relevant examples of feedback-controlled chemical systems. These are the underpinning concepts that hold promise to be combined to form novel adaptive release systems. Furthermore, we motivate the advantages of adaptive release through chronobiological examples. By providing a brief review of these topics and an assessment of the state of the art, we aim to provide a useful resource to accelerate developments in this field. Impact statement The timing and rate of release of pharmaceuticals from advanced drug delivery systems is an important property that has received considerable attention in the scientific literature. Broadly, these mostly fall into two classes: controlled release with a prolonged release rate or triggered release where the drug is rapidly released in response to an environmental stimulus. This review aims to highlight the potential for developing adaptive release systems that more subtlety modulate the drug release profile through continuous communication with its environment facilitated through feedback control. By reviewing the key elements of this approach in one place (fundamental principles of nanomedicine, enzymatic nanoreactors for medical therapies and feedback-controlled chemical systems) and providing additional motivating case studies in the context of chronobiology, we hope to inspire innovative development of novel “chrononanomedicines.”

scholarly journals Injectable and Gellable Chitosan Formulations Filled with Cellulose Nanofibers for Intervertebral Disc Tissue Engineering

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1202 ◽  
Author(s):  
Ingo Doench ◽  
Maria Torres-Ramos ◽  
Alexandra Montembault ◽  
Paula Nunes de Oliveira ◽  
Celia Halimi ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Rheological Behavior ◽  
Biomedical Application ◽  
Flow Behavior ◽  
Cellulose Nanofibers ◽  
Nanofibrillated Cellulose ◽  
The Body ◽  
Mechanical Reinforcement ◽  
Invasive Approach

The development of non-cellularized injectable suspensions of viscous chitosan (CHI) solutions (1.7–3.3% (w/w)), filled with cellulose nanofibers (CNF) (0.02–0.6% (w/w)) of the type nanofibrillated cellulose, was proposed for viscosupplementation of the intervertebral disc nucleus pulposus tissue. The achievement of CNF/CHI formulations which can gel in situ at the disc injection site constitutes a minimally-invasive approach to restore damaged/degenerated discs. We studied physico-chemical aspects of the sol and gel states of the CNF/CHI formulations, including the rheological behavior in relation to injectability (sol state) and fiber mechanical reinforcement (gel state). CNF-CHI interactions could be evidenced by a double flow behavior due to the relaxation of the CHI polymer chains and those interacting with the CNFs. At high shear rates resembling the injection conditions with needles commonly used in surgical treatments, both the reference CHI viscous solutions and those filled with CNFs exhibited similar rheological behavior. The neutralization of the flowing and weakly acidic CNF/CHI suspensions yielded composite hydrogels in which the nanofibers reinforced the CHI matrix. We performed evaluations in relation to the biomedical application, such as the effect of the intradiscal injection of the CNF/CHI formulation in pig and rabbit spine models on disc biomechanics. We showed that the injectable formulations became hydrogels in situ after intradiscal gelation, due to CHI neutralization occurring in contact with the body fluids. No leakage of the injectate through the injection canal was observed and the gelled formulation restored the disc height and loss of mechanical properties, which is commonly related to disc degeneration.

scholarly journals Prostatic Adenocarcinoma Metastatic to Pleomorphic Liposarcoma, a “Collision Phenomenon”: Report of a Case with Review of Pelvic Collision Tumors

2011 ◽  
Vol 2011 ◽  
pp. 1-7
Author(s):  
Somak Roy ◽  
Ronald L. Hrebinko ◽  
Kathleen M. Cieply ◽  
Anil V. Parwani ◽  
Uma N. M. Rao
Keyword(s):  
Pelvic Mass ◽  
Collision Tumor ◽  
The Body ◽  
Pathological Examination ◽  
Prior History ◽  
Pelvic Cavity ◽  
Collision Tumors ◽  
History Of ◽  
Conclusive Diagnosis

“Collision tumor” is an uncommon phenomenon characterized by coexistence of two completely distinct and independent tumors at the same site. Collision tumors have been reported in different sites in the body; however, these are particularly uncommon in the pelvic cavity. A 70-year-old man, with prior history of urothelial and prostate cancer, presented with a large pelvic mass detected on imaging studies. Pathological examination revealed a large liposarcoma with prostatic carcinoma embedded in it. Immunohistochemistry and florescence in situ hybridization studies were performed to reach to a conclusive diagnosis. To the best of our knowledge, this is the second case reported till date. We present the challenges encountered in the diagnosis of this case and review of pelvic collision tumors.

scholarly journals Epidemiology of Melanoma in the Czech Republic in East Bohemia in the Period 2002–2017 and the Effect of the Annual Sunshine Exposure

2020 ◽  
Vol 63 (1) ◽  
pp. 10-17
Author(s):  
Jarmila Čelakovská ◽  
Josef Bukač ◽  
Lenka Čáková ◽  
Marie Šimková ◽  
Eva Jandová
Keyword(s):  
Czech Republic ◽  
The Body ◽  
Body Site ◽  
Lentigo Maligna ◽  
The Czech Republic ◽  
Melanoma In Situ ◽  
Number Of Patients ◽  
Superficial Type ◽  
New Diagnosis

Aim: The evaluation of the trend in the occurrence of melanoma nodulare, melanoma superficiale, lentigo maligna and melanoma in situ in the period of 2002–2017 in East Bohemia region in the Czech Republic. We examine if the annual numbers of hours of sunshine could affect the number of patients with melanoma. Method: In the peridod of 2002–2017, altogether 2230 patients with new diagnosis of melanoma were examined. We studied 1) If there is some trend in the occurrence of lentigo maligna and melanoma in situ, melanoma superficiale, and melanoma nodulare and if there is a difference in the age of patients with this diagnosis (adjusted calculation of specific kind of melanomas and adjusted calculation of age). 2) If the annual numbers of hours of sunshine affect the trend in the occurrence of melanoma and if the annual numbers of hours of sunshine affect the body site of melanoma. Results and conclusion: Our study confirmed that the number of patients with lentigo maligna and melanoma in situ had increased in East Bohemia region in the period of 2002–2017. The number of melanomas of nodular and superficial type does not increase. The total number of melanomas in this period does not increase either. No difference of the age of patients with melanoma nodulare, superficiale, lentigo maligna and melanoma in situ was confirmed. We confirmed no relation of the annual numbers of hours of sunshine to the number of melanoma and to the body site of melanoma.

Design and Fabrication of a Multi-Functional Nanomanipulator

2009 ◽  
Vol 419-420 ◽  
pp. 21-24
Author(s):  
Ming Chang ◽  
Chia Hung Lin ◽  
Chung Po Lin ◽  
Juti Rani Deka
Keyword(s):  
Degrees Of Freedom ◽  
Electrical Characterization ◽  
The Body ◽  
Rapid Expansion ◽  
Nano Materials ◽  
Nano Fabrication ◽  
Permissible Range ◽  
Manipulation System

With rapid expansion of nanotechnology, microminiaturization has become imperative in the field of micro/nano fabrication. A nanomanipulation system with high degrees of freedom that can perform nanomachining, nanofabrication and mechanical/electrical characterization of nanoscale objects inside a scanning electron microscope (SEM) is presented. The manipulation system consists of several individual operating units each having three linear stages and one rotational stage. The body of the manipulator is designed using the idea of superposition. Each operating unit can move in the permissible range of SEM’s vacuum chamber and can increase or decrease the number of units according to the requirement. Experiments were executed to investigate the in-situ electrical resistance of nano materials.

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