Outsourcing Plastic Molding And Mold Making In China, Trust But Verify

Nearly every single plastic molding company in the US and Europe has or is considering sending work to China, no surprise here. The incentives are very real, as are the pressures. Not only are the financial matters pressing, but some customers actually demand a China presence.

Considering the fact that China has become the world’s second largest economy, passing Germany and Japan, the potential for growth is huge, to put it mildly.

Most people recall the very poor quality of Chinese products just a few years ago. Some products are still of very low quality and it seems that you actually get what you pay for in many cases.

On the other hand, the concept of actual built-in quality seems to be slowly sinking into the national mentality, albeit very slowly. Some areas, such as Hong Kong, have a much better tradition of adapting European quality.

When Ronald Reagan was president, he was deeply involved with the arms race with the Soviet Union. One of his favorite phrases was a translation of a Russian proverb: “Trust but verify.” This became his mantra when dealing with Mikhail Gorbachev concerning the INF treaty.

This would be a good mantra for anyone doing plastic molding in China: “Trust but verify.” It seems that the mold makers and molders, and maybe others as well, have a tendency to do what you pay for when you are present, and then cut corners when you are not present.

Without attempting to sound condescending or judgmental, this just is the case. Of course there are countless exceptions, nevertheless, it is still advisable to trust but verify.

A real-life case in point is the fact that American companies usually insist on brand name mold components in their injection molds. Nobody wants a low-grade, soft ejector pin in their mold, for example. So, most people insist on PCS, DME or Progressive ejector pins.

Oddly, after a few thousand shots, the pins bend, break, pit and flake. Yet the pin has PCS etched right into the steel, so how could this be? Simple enough, it was made in a little shop that makes one pin for every company known and just etches whatever name is required. They don’t care if the steel is not H13, just so it works for a while and they make their money.

Anyone who has traveled in developing countries knows about this sort of thing. It happens all the time with just about anything that can be copied or pirated. I once bought a Disney movie before it was in the theaters! You can buy passports, driver’s licenses, birth certificates and anything else you want.

Once you build a working relationship with a Chinese supplier you would think that you are set and don’t need to trust and verify. Wrong. If that were the case, every mold that came in would be right, made using proper techniques and have documented sizes and materials.

That just is not the case, unfortunately, but it doesn’t seem to make much difference to the accounting department in some companies. The mold is so inexpensive that you can just re-work it and still make money. Don’t ask the mold maker about this though.

Find more manufacturers & suppliers: China plastic manufacturer

Mechanical Design of Biomedical Products Using Plastics

Biomedical products typically have physical requirements that differ in some respects from other products. Those requirements usually center on the need for materials and configurations that are compatible with the human body. Not only are such products regulated by FDA requirements, but they must also be able to withstand multiple sterilization cycles involving high temperatures or the use of solvents, or both.

To design parts in the biomedical industry it is necessary to understand the properties of biomedical safe materials, and to understand the constraints on processing those materials to produce sound and economical parts. Not all injection molding factories have both the capability and experience to mold these materials. As an example, parts have been designed and molded both domestically and abroad using Lexan HP2NR and Lexan HPX4. Both of these are FDA approved biocompatibility tested (FDA USP Class VI/ISO10993) plastics.

Lexan HP2NR is clear Polycarbonate plastic. 121C autoclavable for a handful of cycles. As an example, this material is being utilized in a lens for a product used for skin care treatment. The molding resource has been able to mold this material at almost defect free levels in the past 2 years. Lexan HPX4 is a Siloxane copolymer. It performs better in autoclave at 121C (a few dozen cycles, again depends on in-mold stress, morpholine level in autoclave etc. It has a slight haze in its natural state. An example of a biomedical application of this material is a part being colored with FDA approved dye to a gray Pantone 430C color when molded on an oral device used by sleep apnea patients. After molding, the parts go through a thermal press process that creates 300+ features necessary for the retention of the epoxy applied by the user. Parts are thoroughly cleaned in isopropyl alcohol solution, heat dried then bagged and boxed for shipment.

In addition to understanding the issues relating to the materials employed in designing and producing biomedical products it is also necessary to have a good grasp on ergonomic principles and the ability to apply those principles in design. Ergonomics is defined as the study of designing equipment and devices that fit the human body, its movements, and its cognitive abilities. It is always good to consider ergonomics in product design, but in the biomedical arena it is usually critical to the success of the product.

In summary, a successful biomedical product development should be characterized by carefully considered selection of materials and the capability to properly process those materials. Additionally, biomedical product development should also consider a strong dedication to ergonomic principles.

China-plasticmolding cooperates with dozens of Injection Molding Factories, we are a professional Injection Molding Company in China, offers custom injection molding service since 2003.

A Review of Dynamics and Stabilization of the Human Gut Microbiome during the First Year of Life

Background

Dynamics and Stabilization of the Human Gut Microbiome during the First Year of Life was first published on Cell Host &Microbe in 2015. Authors include Fredrik Bckhed and Jovanna Dahlgren.

Experiment Design

Sample: intestinal microbes of 98 mothers and newborn babies (mostly Swedish)

Sequencing strategy: using metagenomic sequencing, a total of 1.52Tb of data, an average of 3.99Gb/sample

Analysis Procedures

  1. Based on the metagenomic data, the gene catalog was established at each time point by de novo assembly, and the KEGG database was used to generate the gene functional annotation.
  2. According to the abundance of different samples, contigs were assembled by binning, and 4356 genomes (>0.9Mb) were obtained by co-assembly. These assembled genomes are supplemented by 1147 genomes in NCBI.
  3. All genomes were subsequently clustered to obtain 690 unique metagenomic OTUs (MetaOTUs), which was equivalent to the classification of species.

Analysis Content

The Phylum Firmicutes and Bacteroides were the most abundant among all detected microorganisms, followed by actinomycetes and proteobacteria. According to the metagenomic data species annotations, a total of 373 MetaOTUs were annotated to the species, and the remaining 317 represented new species that were associated with known species. Most of the MetaOTUs obtained from newborns are also found in mothers, and the abundance is gradually increasing. As revealed by Figure 1, the red area is Novel MetaOTUs, the outer circle is the species annotated to the door level, the inner circle is the species that is gazing to the genus level, and the middle circle represents the abundance of each MetaOTUs of different samples.

Figure 1. MetaOTUs phylogenetic tree

By using unweighted UniFrac distance PCoA analysis of all samples, the samples were clustered according to age. The 12-month neonatal situation was most similar to that of the mother, because the neonatal intestinal microflora structure had stabilized.

With age growing, the alpha diversity in the neonatal intestinal flora gradually increased, while the beta diversity gradually decreased, indicating that the microbial species in the community became more complex, and the differences between communities became smaller.

Next, the authors performed a comparison of the gut microbiota structure of neonates with C-section and vaginally born. The result turned out to be consistent with the PCoA results. As the age increases, the bacterial composition tends to approach mothers. However, due to the absence of maternal birth canal, the number of maternal microorganisms obtained at the time of birth is small. Compared with the vaginally newborn, their establishment of microorganisms in the intestine is slow and some of the flora is missing.

Figure 2. A comparison of the gut microbiota structure of neonates with C-section and vaginally born

The metagenomic analysis also reveals the energy utilization of the neonatal intestinal flora over time. The function of the fecal flora in the first year of delivery is improved, and the phosphotransferase system (PTS) gene related to carbohydrate absorption is rich in the neonatal intestinal flora.

The gut flora of neonatal and 4-month-old neonatal is enriched with the gene that digests the sugar in the breast milk, at which point the sugar is the main source of energy. The β-glucose-specific transporter is the most abundant in newborns at 4 months and 12 months of age. The intestinal flora of 12-month-old newborns is enriched with genes that break down polysaccharides and starch and is associated with an increase in Bacteroides variabilis, which has all the enzymes involved in polysaccharide digestion.

Figure 3. KO pathway

Bacteria in the gut of virginally newborns include: Enterococcus, Escherichia/Shigella, Streptococcus, and Rothia Geory and Brown, indicating a relatively oxygen-rich intestinal environment. The 4-month neonatal gut flora is characterized by Bifidobacterium, Lactobacillus, Collins, Granulicatella, and Vesococcus, indicating a gradual decrease in intestinal oxygen concentration and an increase in the ability to produce and utilize lactic acid. The diet at this time is mainly breast milk.

The characteristics of the 12-month neonatal gut flora include: bacteria found in newborns and in 4-month old newborns (as previously listed), and only present in 12 months Bacteria, such as the genus Eichhornia.

Figure 4. Characteristics of intestinal flora in different periods of caesarean section

Summary

As an important research tool, metagenomics can get a lot of high-value information in the process of microbial population research. It is of great significance for further research on microbial-related metabolism and immunity.

Features of CD Genomics Metagenomic Sequencing

  1. Rich experience in sample processing

Such as soil, sediment, intestinal contents, manure, water, air, dairy products…CD Genomics has rich experience in various sample extraction;

  1. High quality data

CD Genomics has a wide range of technical platforms to obtain high quality data;

  1. Satisfactory analysis report

More database annotations for more analysis results

  1. Deep data mining capacity and comprehensive follow-up customer services

CD Genomics has professional bioinformatics analysis team, powerful experimental and sequencing platform to provide microbial genome de novo resequencing16S/18S/ITS, metagenomics, transcriptome sequencing and other micro-site one-stop sequencing analysis services.

Handbook of 16S rDNA Sequencing: The Past and the Present

The basic concept of 16S rDNA

16S rDNA is one of most useful and most commonly used molecular clocks in the systematic classification of bacteria. It has few species but large content (about 80% of bacterial RNA content). Its molecular size is moderate and exists in all organisms. Its evolution has been smooth and is highly conservative in structure and function. It is known as “bacterial fossil”. In most prokaryotes, rDNA has multiple copies, and the copy number of 5S, 16S, and 23S rDNA is the same. 16S rDNA is moderately sized, about 1.5Kb, which can reflect the differences between various strains, and can be easily obtained by sequencing technology, so it is widely accepted by bacteriologists and taxonomists. In short, 16S rDNA is universal, conservative, moderately sized and has variable zone.

To be more specific, this article summarizes its features as follows:

1. 16S rRNA is ubiquitous in prokaryotes. rRNA is involved in the process of protein synthesis. Its function is essential to any organism, and it remains unchanged during the long course of biological evolution. It can be seen as a time clock for biological evolution.

2. In 16S rRNA molecule, it contains both highly conserved sequence regions and moderately conserved and highly variable sequence regions, so it is suitable for the study of various biological phylogenetic relationships with different evolutionary distances.

3. The relative molecular weight of 16S rRNA is moderate, about 1540 nucleotides, which is convenient for sequence analysis.

4. The variable region sequence varies from bacteria to bacteria, and the constant region sequence is basically conserved. Therefore, primers can be designed by using the constant region sequence to amplify the 16S rDNA fragment, and the difference between the variable region sequences can be used for different genus and strains. Based on this, the bacteria were classified and identified.

16S structure

The 16S rRNA gene sequence includes 9 variable regions and 10 conserved regions. The conserved region sequence reflects the genetic relationship between species, while the variable region sequence reflects the differences between species.

Figure 1. 16S rRNA gene sequence

Strain identification based on 16S full-length (first generation sequencing)

Object: pure colonies that have been cultivated

Technology: first generation sequencer 3730

Process: Nucleic Acid Extraction –> Gene Amplification –> Product Purification –> Sequencing Reaction –> Sequence Alignment

a.

Graph LR

b.

Nucleic Acid Extraction–>Gene Amplification

c.

Gene amplification–>product purification

d.

Product purification–>sequencing reaction

e.

Sequencing reaction–>sequence alignment

Commonly used primer sequence by 16S full length (see Table 1):

Table 1. Commonly used primer sequence by 16S full length

Reagent cost: about $15

Advantages: it can assist routine strain identification methods, such as microscopic morphology and culture characteristics as well as physical and chemical properties, including nutrient type, carbon and nitrogen source utilization capacity, various metabolic reactions, enzyme reactions and serological reactions, etc., to improve the accuracy of strain identification.

Disadvantages: it can only be used for pure bacteria!

Bacterial structure analysis based on 16S (Next-generation sequencing)

Objects: clinical samples (such as feces, cerebrospinal fluid, blood, urine, etc.), environmental samples (soil, sewage, etc.)

Technology: second-generation sequencers, such as Hiseq and Miseq from Illumina, Ion Torrent from Thermo, and 454 from Roche (discontinued)

Process: Genomic DNA –> Sample Quality Control –> PCR Amplification Database –> Library Quality Control –> Illumina Hiseq2500/Miseq Sequencing –> Raw Data –> Data Quality Control –> High Quality Data –> Bioinformatics Analysis

Some commonly used primer sequences are listed in Table 2.

Table 2. Primer selection table for specific 16S rRNA gene region to be amplified

Reagent cost: about $15 ~ $60/sample, determined by the use of consumable grade and labor costs.

Advantages: By detecting the sequence variation and abundance of 16S rDNA, the classification and abundance of bacteria is revealed in the sample, obtaining sample species classification, species abundance, population structure, phylogenetic evolution, community comparison, etc., which can be used for detection of unknown clinical samples and finding pathogens.

Disadvantages:

(1) Limited by the read length of the second-generation sequencing, currently only two of the nine variable regions of 16S can be measured, generally the V3-V4 region. Therefore, for the resolution of the flora, some strains can only be distinguished to the genus level.

(2) Lack of SOP experimental program. Different experimental factors have a greater impact on the experimental results.

(3) The 16S metagenomics can also be used for functional studies, but not accurate, compared to the WGS metagenomic sequencing.

The Future of 16S: Third Generation Sequencing

Pacbio sequencing technology for 16S metagenomics has been published. A reference article: High-resolution phylogenetic microbial community profiling.

9 variable areas are tested on the machine, with high resolution and high accuracy, which is more suitable for unknown pathogen detection and other scientific research applications in clinical samples.

Unfortunately, due to unresolved sample pooling and other reasons, its price remains high.

About author:

As a leading provider of NGS services and a partner of Illumina, CD Genomics offers a portfolio of solutions for metagenomics sequencing. 16S/18S/ITS amplicon sequencing is characterized by cost-efficiency, high-speed and practicability to help you identify and investigate the microbial community. With over 10 years of experience, we can totally meet your project requirements and budgets in the exploration of microbial biodiversity.