Most conifer species have needle-shaped leaves that are only a few centimeters long. In general, variation in leaf size has been associated with environmental factors, such as cold or drought stress. However, it has recently been proposed that sugar export efficiency is the limiting factor for conifer needle length, based on the results obtained using a mathematical model of phloem transport. Here, phloem transport rates in long conifer needles were experimentally determined to test if the mathematical model accurately represents phloem transport. The validity of the model's assumptions was tested by anatomical analyses and sugar quantification. Furthermore, various environmental and physiological factors were tested for their correlation with needle length. The results indicate that needle length is not limited by sugar transport efficiency, but, instead, by winter temperatures and light availability. The identification of factors that influence needle size is instrumental for using this trait as a variable in breeding programs.
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http://dx.doi.org/10.1093/treephys/tpy056 | DOI Listing |
Int J Clin Pediatr Dent
December 2024
Department of Pedodontics and Preventive Dentistry, Vivekanandha Dental College for Women, Namakkal, Tamil Nadu, India.
Background And Objective: During the last 200 years, there have been many changes in the way of performing endodontic treatment. The increased demand from patients for saving their teeth has led to the development of various innovative equipment and advances in the field of material sciences. Thus, the standard protocol of endodontic treatment has undergone several modifications.
View Article and Find Full Text PDFPharmaceutics
January 2025
Department of Pharmaceutical Technology and Biopharmacy, University of Groningen, 9713 AV Groningen, The Netherlands.
The application of dissolving microneedle arrays (DMNAs) is an emerging trend in drug and vaccine delivery as an alternative for hypodermic needles or other less convenient drug administration methods. The major benefits include, amongst others, that no trained healthcare personnel is required and that the recipient experiences hardly any pain during administration. However, for a successful drug or vaccine delivery from the DMNA, the microneedles should be inserted intact into the skin.
View Article and Find Full Text PDFPharmaceutics
January 2025
Department of Mathematics, Visva-Bharati University, Santiniketan 731235, WB, India.
Microneedle(MN)-based drug delivery is one of the potential approaches to overcome the limitations of oral and hypodermic needle delivery. An in silico model has been developed for hollow microneedle (HMN)-based drug delivery in the skin and its subsequent absorption in the blood and tissue compartments in the presence of interstitial flow. The drug's reversible specific saturable binding to its receptors and the kinetics of reversible absorption across the blood and tissue compartments have been taken into account.
View Article and Find Full Text PDFJ Laparoendosc Adv Surg Tech A
January 2025
Department of Surgical Disciplines, All India Institute of Medical Sciences, New Delhi, India.
Laparo-endoscopic hernia surgery is recommended by various international bodies. However, its uptake by general surgeon is low. We aim to assess the impact of Three Dimensional (3D) endovision system in learning laparoscopic transabdominal preperitoneal (TAPP) repair of groin hernia and transferability of skills acquired from 3D to the Two Dimensional (2D) environment.
View Article and Find Full Text PDFFront Bioeng Biotechnol
January 2025
Department of BioMechanical Engineering, Bio-Inspired Technology Group, Faculty of Mechanical Engineering, Delft University of Technology, Delft, Netherlands.
Percutaneous pancreatic core biopsy is conclusive but challenging due to large-diameter needles, while smaller-diameter needles used in aspiration methods suffer from buckling and clogging. Inspired by the ovipositor of parasitic wasps, which resists buckling through self-propulsion and prevents clogging via friction-based transport, research has led to the integration of these functionalities into multi-segment needle designs or tissue transport system designs. This study aimed to combine these wasp-inspired functionalities into a single biopsy needle by changing the interconnection of the needle segments.
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